# DRAFT

FLORIDA DEPARTMENT OF ENVIRONMENTAL PROTECTION

Division of Water Resource Management, Bureau of Watershed Management



### SOUTHWEST DISTRICT • LAKE HANCOC K BASIN • PEACE RIVER PLANNING UNIT 

# TMDL Report 

# Dissolved Oxygen and Nutrient TMDLs for Lake Hancock and Lower Saddle Creek (WBID 1623L & 1623K)

Zack Shelley Douglas Gilbert Kevin Petrus

November 2005DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## i 

# Acknowledgments

This study could not have been accomplished without si gnificant contributions from staff in the Florida Department of Environmental Protec tion’s (the Department) Watershed Assessment Section. The Department also recognizes t he substantial support and assistance from the Department’s Tampa District Office, the Southwes t Florida Water Management District (SWFWMD), the Polk County Natural Resource Division, Soil and Water Engineering Technology, Inc. (SWET), and Quantitative Environmental Analysis (QEA), LLC, and their contributions towards understanding the issues, history, and processes at work in the Lake Hancock and Lower Saddle Creek watersheds.

Editorial assistance provided by Daryll Joyner and Jan Mandrup-Poulsen.

For additional information on the watershed management approach and impaired waters in The Peace River, Myakka River, and Sarasota Bay Planning Units, contact:

Tom Singleton Florida Department of Environmental Protection Bureau of Watershed Management Watershed Planning and Coordination Section 2600 Blair Stone Road, Mail Station 3565 Tallahassee, FL 32399-2400 tom.singleton@dep.state.fl.us Phone: (850) 245-8561; Suncom: 205-8561 Fax: (850) 245-8434

Access to all data used in the development of this report can be obtained by contacting:

Kevin Petrus, Environmental Manager Florida Department of Environmental Protection Bureau of Watershed Management Watershed Assessment Section 2600 Blair Stone Road, Mail Station 3555 Tallahassee, FL 32399-2400 Kevin.petrus@dep.state.fl.us Phone: (850) 245-8459; Suncom: 205-8459 Fax: (850) 245-8536DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## ii 

# Contents

CHAPTER 1: INTRODUCTION................................................................................................. 1 1.1 Purpose of Report ......................................................................................................... ...1 1.2 Identification of Waterbody .............................................................................................1 1.3 Lake Hancock Historic Water Quality.............................................................................7 1.4 Lake Hancock Background Information.........................................................................9 1.5 TMDL Background Information.....................................................................................10



### CHAPTER 2: STATEMENT OF WATER QUALITY PROBLEM ......................................... 12

2.1 Legislative and Rulemaking History.............................................................................12 2.2 Information on Verified Impairment..............................................................................12


### CHAPTER 3. DESCRIPTION OF APPLIC ABLE WATER QUALITY STANDARDS AND TARGETS........................................................................................................................ ............. 25

3.1 Classification of the Waterbody and Criteria Applicable to the TMDL ......................25 3.2 Dissolved Oxygen Criterion for Lakes and Streams...................................................25 3.3 Interpretation of the Narrative Nutrient Criteria for Lakes and Streams.................26
3.3.1 Criteria Definitions..................................................................................................... ...28 3.4 Paleolimnological Information for the Lake Hancock Basin ......................................29
Lake Hancock................................................................................................................... ......29 Lake Hollingsworth............................................................................................................. ...30
Lake Parker .................................................................................................................... ........30


### CHAPTER 4: ASSESSMENT OF SOURCES.......................................................................... 32

4.1 Overview of Modeling Process......................................................................................32
4.2 Potential Sources of Nutrients in the Lake Hancock and Lower Saddle Creek Watersheds ..................................................................................................................... .......34
4.2.1 Point Sources........................................................................................................... ....34
Lake Lena Sub-basin............................................................................................................ .34
Lake Parker Sub-basin.......................................................................................................... 35 Municipal Separate Storm Sewer System Permittees........................................................37 4.2.2 Nonpoint Sources and Land Uses ..............................................................................39 Polk County Population ........................................................................................................4 3 Polk County Septic Systems ................................................................................................43 4.3 Estimating Point and Nonpoint Source Loadings...............................................43DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## iii Model Approach ................................................................................................................. ...43
Land Use and Soils ............................................................................................................. ..46 Hydrologic Data ................................................................................................................ .....46 Depressions.................................................................................................................... .......47
Rainfall....................................................................................................................... .............49
Control Structures............................................................................................................. ....49
Ground Water................................................................................................................... ......49 WAM Model Linkage to the BATHTUB Model .....................................................................51
WAM and BATHTUB Calibration ..........................................................................................51 Lake Hancock Basin Existing Land Use Loadings ............................................................52


### CHAPTER 5: DETERMINATION OF ASSIMILATIVE CAPACITY ................................... 56 5.1 Determination of Loading Capacity ..............................................................................56
5.1.1 Rainfall................................................................................................................ ..........56
5.1.2 Model Calibration ....................................................................................................... .57 Watershed Assessment Model (WAM) ................................................................................57
BATHTUB Model.................................................................................................................. ..57 5.1.3 Background Conditions..............................................................................................60
WAM Model ...................................................................................................................... ......60
BATHTUB Model.................................................................................................................. ..61 5.2 Selection of the TMDL Target........................................................................................61
5.3 Critical Conditions....................................................................................................... ...67
5.4 Wasteload Allocation .....................................................................................................6 7


### CHAPTER 6: DETERMINATION OF THE TMDL................................................................ 74 6.1 Expression and Allocation of the TMDL.......................................................................74 6.2 Load Allocation (LA) ...................................................................................................... 75 6.3 Wasteload Allocation (WLA)..........................................................................................75 NPDES Wastewater Discharges...........................................................................................75 NPDES Stormwater Discharges ...........................................................................................75 6.4 Margin of Safety (MOS) ..................................................................................................75
6.5 Lower Saddle Creek .......................................................................................................7 6


### CHAPTER 7: NEXT STEPS: IMPLE MENTATION PLAN DEVELOPMENT AND
BEYOND ......................................................................................................................... ............. 77
REFERENCES ..................................................................................................................... ....... 78
APPENDICES .................................................................................................................... ........ 83DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## iv Appendix A: Background Information on Federal and State Stormwater Programs.....83 Appendix B: Lake Hancock and Lower Saddle Creek Total Nitrogen, Total Phosphorus, Chlorophyll a , and Dissolved Oxygen Monitoring Data.....................................................84 Appendix C: Lake Hancock Basin Modeled Lakes TSI for PC, Background, TMDL Target, and TSI-Unit Percent Reduction.............................................

. Separate Attachment Appendix D: Lake Hancock Basin Modeled Lakes Mass for TN and TP for Calibrated Model, TMDL, and Percent Reduction ................................................

. Separate Attachment Appendix E: Lake Hancock Basin Modeled Lakes Annual Average Concentrations for TN, TP, and Chlorophyll a

......................................................... . Separate Attachment Appendix F: SWET Watershed Assessment Model (WAM) of the Lake Hancock Basin Final Report................................................................................................................... .......105 Appendix G: QEA BATHTUB Model Framework for the Lake Hancock Basin Final Report............................................. ..................................................... ....105 Appendix H: WAM Watershed Assessment Model, Model Documentation and Users Manual, Soil and Water Engineering Technology, Inc., May, 2005............................105



### Tables

Table 1.1 Summary Statistics of Historical Water Quality in Lake Hancock form 1985 to 1999.....................7 Table 1.2 Summary Statistics of Historical Wate r Quality in Lake Hancock from March 2004 to February 2005............................................................................................................................8 Table 2.1 Water Quality Summary Statistics for TN, TP, and Chlorophyll a for Lake Hancock and Lower Saddle Creek from 1992 to 2004.....................

................................................................ .................12 Table 3.1 Screening Level Values Based on STORET Data from 1979 to 1987.........................................23 Table 4.1 Lake Hancock Basin Existing Land Use Descriptions. ..........................................................34 Table 4.2 Lake Gibson and Lake Crago Existing Land Use Water Volume and Loadings for TN and TP From 1994 to 2003.....................................................................................................................53 Table 4.3 Lake Bonny and Lake Parker Existing Land Use Water Volume and Loadings for TN and TP From 1994 to 2003.....................................................................................................................53 Table 4.4 Lake Lena and Lake Banana Existing Land Use Water Volume and Loadings for TN and TP From 1994 to 2003.....................................................................................................................54 Table 4.5 Lake Hancock and Lake Hollingsworth Existing Land Use Water Volume and Loadings for TN and TP from 1994 to 2003.................................................................................................................54 Table 4.6 Lake Bentley and Lake Spirit Existing Land Use Water Volume and Loadings for TN and TP from 1994 to 2003......................................................................................................................55 Table 4.7 Lake Eagle Existing Land Use Water Volume and Loadings for TN and TP from 1994 to 2003.......................................................................................................................................55 Table 5.1 Bartow and Lakeland, Florida, Rainfall Stations used for Model Loading and Calibration............57 Table 5.2 Lake Hancock TSI for PC, Background, TMDL Target, and TSI-Unit Reduction........................63 Table 5.3 Lake Hancock Mass for TN and TP for Calibrated Model, TMDL, and Percent Reductions..........63 Table 5.4 Lake Hancock Annual Average Concentrations for TN, TP, and Chlorophyll a ...........................64 Table 5.5 Flow in Cubic Hectometers Per Year for Each Source

....................................... .............. ..........68 Table 5.6 Difference Between PSPC and PSMAX and PSPC and NoPS Flow (h m3/yr).............................69 Table 5.7 Total Phosphorus Mass (kg/yr)...................................................................................................70 Table 5.8 Total Phosphorus Mass Differenc e Between PSPC and PSMAX and PSPC and NoPS..............71 Table 5.9 Total Nitrogen Mass (k g/yr).................................

................. .................. .................. ........... ........7 2 Table 5.10 Total Nitrogen Mass Differenc e Between PSPC and PSMAX and PSPC and NoPS.................73 Table 6.1 Lake Hancock and Lower Saddle Cr eek TMDL Load Allocati ons............................................74DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## v Figures

Figure 1.1 Southwest Florida Group 3 WBIDs and Major Metropolitan Areas Surrounding the Lake Hancock Watershed and Lower Saddle Creek Sub-basin...............................................................3 Figure 1.2 Lake Hancock WB ID 1549B and Monitoring Stations.......................................................5 Figure 1.3 Lower Saddl e Creek Canal WBID 1549A and M onitoring Stations......................................6 Figure 2.1 TSI Results for Lake Ha ncock Calculated from Annual Av erage Concentrations of TN, TP, and Chlorophyll a from 1984 to 2004............................

.................. .................. ................ .............. ............15 Figure 2.2 Total Nitrogen Mont hly Results for Lake Hancock from 1992 to 2004.................................15 Figure 2.3 Total Nitrogen Annual Mean Results for Lake Hancock from 1992 to 2004..........................16 Figure 2.4 Total Phosphor us Monthly Results for Lake Hancoc k from 1992 to 2004...

................... .........16 Figure 2.5 Total Phosphorus A nnual Mean Results fo r Lake Hancock from 1992 to 2004......................17 Figure 2.6 Chlorophyll a Monthly Results for La ke Hancock from 1992 to 2004...................

........... .......17 Figure 2.7 Chlorophyll a Annual Mean Results for Lake Hanc ock from 1992 to 2004............................18 Figure 2.8 Dissolved Oxygen Monthl y Results for Lake Hancock from 1992 to 2004............

............. ......18 Figure 2.9 Dissolved Oxygen Annual Mean Results for Lake Hancock from 1992 to 2004.....................19 Figure 2.10 Total Nitrogen Monthly Results for Saddle Creek Below Lake Hancock from 1992 to 2004........................

................... .................. .................. .................. ............... ............. ..............................19 Figure 2.11 Total Nitrogen Annual Mean Results for Saddle Creek Below Lake Hancock from 1992 to 2004...............................................................................................................................20 Figure 2.12 Total Phosphorus Monthly Results for Saddle Creek Below Lake Hancock from 1992 to 2004..................

.................. .................. .................. ................... ............... ................. ................................20 Figure 2.13 Total Phosphorus Annual Mean Results for Saddle Creek Below Lake Hancock from 1992 To 2004.............................................................................................................................21 Figure 2.14 Chlorophyll a Monthly Results for Saddle Creek Below Lake Hancock from 1992 to 2004........................

................... .................. .................. .................. ............... ............. .............................21 Figure 2.15 Chlorophyll a Annual Mean Results for Lower Saddle Creek from 1992 to 2004..............................

.................. ................... ............... ................ ................ ............... ........................22 Figure 2.16 Dissolved Oxygen Mont hly Results for Saddle Creek Below Lake Hancock from 1992 to 2004...............................................................................................................................22 Figure 2.17 Dissolved Oxygen Annual Mean Results fo r Saddle Creek Below Lake Hancock from 1992 to 2004...............................................................................................................................23 Figure 4.1 Aerial View of the Lake Hancoc k and Saddle Creek Watershed, Polk, County, Florida................................................................................................................................33 Figure 4.2 Lake Hancock and Lower Saddle Creek Watershed Lake Control Structures and Active NPDES Facilities

.............................. .................................................... .................................36 Figure 4.3 Phase I MS4 Coverage Area for t he Lake Hancock Basin...............................................38 Figure 4.4 Lake Hanc ock and Saddle Creek Existing Land Use Cover age..........................................41 Figure 4.5 Lake Hancock Basin Natural Background Land Use Cove rage.........................................42 Figure 4.6 WAM Conceptual Routing Di agram............................................. .................................44 Figure 4.7 WAM Dynamic Modeling Ap proach................................... ...........................................45 Figure 4.8 Model Schematic Depicting the Intercon nected Eleven Lakes Modeled for the Lake Hancock Watershed..........................................................................................................................46 Figure 4.9 Model Reaches and Estimated Depre ssions Attenuation Distances...................................47 Figure 4.10 Rainfall Stations and Z ones......................................................................................49 Figure 4.11 Surface Water and Ground Water Distribution Z ones.....................................................50 Figure 5.1 Lake Hancock Total Nitrogen Measur ed, Un-Calibrated and Calibrated Data from 1994 to 2003...............

................... ................... .............. .................. ............... ............... ...........................58 Figure 5.2 Lake Hancock Total Phosphorus Measured, Un-Calibrated and Calibrated Data from 1994 to 2003.......................................................................................................................59 Figure 5.3 Lake Hancock Chlorophyll a Measured, Un-Calibrated and Calibrated Data from 1994 to 2003.......................................................................................................................59 Figure 5.4 Lake Hancock TSI Measured, Un-Calib rated and Calibrated Data from 1994 to 2003...........60 Figure 5.5 Lake Hancock Total Nitrogen Target TMDL, Background Calibration, and L50-IL75 from 1994 to 2003................................................................................................................65DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## vi Figure 5.6 Lake Hancock Total Phosphorus Target TMDL, Background Calibration, and L50-IL75 from 1994 to 2003...............................................................................................................65 Figure 5.7 Lake Hancock Chlorophyll a Target TMDL, Background Calibration, and L50-IL75 from 1994 to 2003................................................................................................................66 Figure 5.8 Hancock TSI Target TMDL, Background Calibration, and L50-IL75 from 1994 to 2003.........................................................................................................................66DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## vii Web sites

FLORIDA DEPARTMENT OF ENVIRONMENTAL PROTECTION, BUREAU OF WATERSHED MANAGEMENT

TMDL Program http://www.dep.state.fl.us/water/tmdl/index.htm Identification of Impaired Surface Waters Rule http://www.dep.state.fl.us/water/tmdl/docs/AmendedIWR.pdf STORET Program http://www.dep.state.fl.us/water/storet/index.htm 2000 305(b) Report http://www.dep.state.fl.us/water/305b/index.htm Criteria for Surface Water Quality Classifications http://www/dep.state.fl.us/legal/legaldocuments/rules/ruleslistnum.htm Basin Status Report for the Lake Hunter Basin http://www.dep.state.fl.us/water/tmdl/stat_rep.htm Assessment Report for the Lake Hunter Basin http://www.dep.state.fl.us/water/tmdl/stat_rep.htm Allocation Technical Advisory Committee (ATAC) Report http://www.dep.state.fl.us/water/tmdl/docs/Allocation.pdf



### U.S. ENVIRONMENTAL PROTECTION AG ENCY, NATIONAL STORET PROGRAM

http://www.epa.gov/storet/DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 1 

# Chapter 1: INTRODUCTION

1.1 Purpose of Report

This report presents the Total Maximum Daily Load (TMDL) for nutrients and dissolved oxygen (DO) for Lake Hancock and Saddle Creek Below Lake Hancock, which are located in the Lake Hancock Basin. For this TMDL report, the Saddle Creek Below Lake Hancock waterbody will be referred to as “Lower Saddle Creek.” Lake Hancock and Lower Saddle Creek are essentially the headwaters of the Peace River and have a direct impact on water quantity and quality of the downstream river reaches. The lake and creek were verified as impaired for nutrients and low DO using the methodology in the Identification of Impaired Surface Waters Rule [IWR, Rule 62-303, Florida Administrative Code (F.A.C.)]. The lake and creek were included on the Verified List of impaired waters that was adopted by Secretarial Order on June 17, 2005. The TMDLs establish the allowable loadings to the lake and creek that would restore the waterbodies so that they meet their applicable water quality criteria for nutrients and DO.


### 1.2 Identification of Waterbody

Lake Hancock is located southeast of the City of Lakeland, north of Bartow and west of Winter Haven in Polk County, Florida. The estimated surface area of the lake is 4,533 acres, and the approximate total volume of the lake is 19,795,031.5 m 3 

### (16,048 acre-feet), with an average depth of 5 ft (1.5 m). The surface water drainage area of the lake is approximately 140 square miles. The surface water drainage area of Lake Hancock and Lower Saddle Creek is approximately 157 square miles. The Lake Hancock and Lower Saddle Creek watersheds are illustrated in Figure 1.1, which also shows the eight major sub-basins that make up the Lake Hancock watershed. The watershed’s land use designations are primarily urban, citrus, and abandoned phosphate mine lands. The normal pool topographic elevation of the water surface is approximately 97.7 feet National G eodetic Vertical Datum (NGVD) (BCI Engineers and Scientists, Inc., 2005). Primary tributar ies flowing into Lake Hancock include Banana Lake Canal, Lake Lena Run, and Saddle Creek Above Lake Hancock (here after referred to as Middle and Upper Saddle Creek).
Significant sub-basins draining into Lake Hancock and Lower Saddle Creek include Middle and Upper Saddle Creek, the Lake Parker sub-basin (which includes Lakes Bonny, Gibson, Crago, and Parker); the Banana Lake sub-basin (which includes Lakes Bentley, Hollingsworth, Banana, and Banana Lake Canal); the Lake Lena sub-basin (which includes Lakes Areitta, Ariana, Lena, and Lake Lena Run); and the Eagle Lake sub-basin (which includes Lakes Thomas, Sears, Spirit, Eagle, and Millsite).

Lower Saddle Creek is the outlet channel for Lake Hancock. The creek’s confluence with the Peace Creek Drainage Canal forms the headwaters of the Peace River, which travels approximately 105 miles to Charlotte Harbor. In 1963, the Outfall Control Structure P-11 was constructed approximately 3,500 feet south of Lake Hancock in Lower Saddle Creek to regulate discharge from the lake and reduce flooding in downstream reaches during high rainfall/water events (Environmental Research and Design, Inc., 1999). Structure P-11 was constructed to replace a structure that consisted of concrete, timber piles, and removable boards. This current structure is operated and maintained by the Southwest Florida Water Management District (District). Two 7-foot high by 20-foot wide radial gates with an invert of 91.7 feet NGVD are used to regulate the flows out of the lake. Since construction of the P-11DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 2 structure, the water level in the lake has averaged between elevations of 97 and 98.5 feet NGVD (BCI Engineers and Scientists, Inc., 2005).DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 3 Figure 1.1 Southwest Florida Group 3 WBIDs and Major Metropolitan Areas Surrounding the Lake Hancock Watershed and its Major Sub-basinsDRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 4 For assessment purposes, the Department has divided the Lake Hancock Basin into water assessment polygons with a unique w ater b ody id entification (WBID) number for each watershed or stream reach. The lake has been given the WBID number of 1623L, and Lower Saddle Creek has been given the WBID num ber 1623K. The Lake Hancock WBID and its sampling/monitoring stations are shown in Figure 1.2. The Lower Saddle Creek WBID and its sampling/monitoring stations are shown in Figure 1.3.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 5 Figure 1.2 Lake Hancock (WBID 1623L) and Monitoring StationsDRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 6 Figure 1.3 Lower Saddle Creek (WBID 1623K) and Monitoring StationsDRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 7 1.3 Lake Hancock Historic Water Quality

Concerns over water quality problems in Lake Hancock date back to the early 1950s. In this time-frame, Lake Hancock has been heavily impacted by man-made activities, including domestic waste and industrial wastewater treatment plant discharges from the cities of Lakeland, Winter Haven, and Auburndale, urban development, agricultural activities, wetland destruction, and phosphate mining. And as a result, the lake began and continued to develop high nutrient concentrations. Accumulation of organic matter within the lake began and continued to occur as a result of the hypereutrophic conditions and the continued herbicide treatments to control water hyacinths (ERD, 1999).
A routine water quality monitoring program was initiated for Lake Hancock by Polk County in 1984. A total of 32 separate surface water monitoring events were performed over a 16-year period from 1984-1999, for a mean of two m onitoring events each year. The lake was characterized as having extremely elevated levels of pH, total nitrogen, total phosphorus, turbidity, and chlorophyll a.
According to Environmental Research and Design, Inc., (1999), measured concentrations of total nitrogen (TN) were 3-4 times greater than values observed in most urban lake systems. Total phosphorus (TP) concentrations were approximately 10-20 times greater and chlorophyll

a

concentrations approximately 5-10 times greater. A summary of mean water quality characteristic measured in Lake Hancock are displayed in Table 1.1

. Table 1.1 Summary Statistics of Historical Water Quality in Lake Hancock from 1985 to 1999 Summary Statistics of Historical Water Quality Characteristics in Lake Hancock from 1985-1999

Water Quality Variable Units Mean Value Minimum Value Maximum Value pH s.u. 9.18 7.38 10.13 Dissolved Oxygen mg/L 8.6 0.9 15.7 Temperature o C 24.0 15.6 34.3 Specific Conductance μ mho/cm 275 170 456 Secchi Depth meters 0.2 0.1 0.6 NH3-N mg/L 0.037 BDL 0.2 Nox-N mg/L 0.01 BDL 0.05 Organic N mg/L 5.95 1.47 15.4 Total N mg/L 5.99 1.51 15.63 Total P mg/L 0.63 1.05 2.87 Turbidity NTU 44.6 4.3 104 Color Pt-Co 58 27 100 Chlorophyll a mg/m3 170 34 350 Environmental Research and Design, Inc., December, 1999. BDL-Below Detectable Limits.


### Historically, water quality in Lake Hancock has been variable, particularly for the water quality variables pH, dissolved oxygen (DO), TN, TP, turbidity, and chlorophyll a . DO concentrations ranged near near-anoxic conditions to supersaturated conditions. TN concentrations varied from 1.51 to 15.63 milligrams per liter (mg/L). TP concentrations varied from .11 to 2.87 mg/L.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 8 Variations in TN/TP rations also occurred in this time period. Based on historic ratios, the lakeoscillated between nutrient-balanced conditions to phosphoruslimited and nitrogen limited conditions. A 25-fold difference in turbidity values was observed with a 10-fold difference observed for chlorophyll a . With a few exceptions, Lake Hancock has consistently exhibited hypereutrophic c onditions from 1985 to 1999, with calculated annual mean trophic state index (TSI) values ranging from 67 to 101 and a mean TSI of 91. Note, TSI values were based entirely on chlorophyll a concentrations because the watercolumn concentration of TP and measured Secchi depth were impacted heavily by the resuspension of bottom sediments as a result of consistent wind action (ERD, 1999)

ERD also conducted surface water quality monitoring at three sites in Lake Hancock from March 2004-February 2005 in support of the Lake Hancock Outfall Treatment System Evaluation, funded by the Southwest Florida Water Management District (SWFWMD). See Table 1.2 for the means and ranges of water quality variables measured for Lake Hancock from 2004 to 2005.

Table 1.2 Summary Statistics of Historical Water Quality in Lake Hancock from March 2004 to February 2005 Summary Statistics for Surface Water Samp les Collected in Lake Hancock from March 2004 to February 2005 Sample Site 1 Sample Site 2 Sample Site 3 Water Qaulity Variable Units Mean Range Mean Range Mean Range Alkalinity mg/L 63.9 47.7-80.2 63.2 49.5-80.0 61 33.7-82.8 NH3 mg/L 0.23 0.12-1.613 0. 15 .010-0.760 0.15 .012-0.594 NOx mg/L 0.02 0.005-0.171 0. 02 0.005-0.147 0.03 0.005-0.237 Dissolved Organic N mg/L 0.91 0. 188-1.416 1.22 0.115-3. 237 1.02 0.316-1.750 Particulate N mg/L 2.91 1.590- 5.544 2.45 0.192-4. 713 2.48 0.555-4.384 Total N mg/L 4.08 2.386-7.090 3.84 2.291-6.398 3.67 1.414-5.591 SRP mg/L 0.10 0.001-0.358 0. 10 0.001-0.357 0.12 0.001-0.374 Dissolved Organic P mg/L 0.02 0. 005-0.062 0.02 0.006-0. 058 0.02 0.004-0.047 Particulate P mg/L 0.35 0.140- 0.691 0.33 0.121-0. 604 0.29 0.090-0.569 Total P mg/L 0.48 0.153-0.716 0.45 0.133-0.630 0.42 0.113-0.592 Turbidity NTU 27.9 11.2-52.2 27.4 9.7-46.7 22.2 8.1-44.5 TSS mg/L 71.3 16.0-164 66.9 14.4-150 52.4 13.3-157 COD mg/L 137 53-278 132 51-294 117 55-224 BOD mg/L 14.9 5.8-27.4 14. 7 5.4-24.1 12.1 4.6-20.8 Color Pt-Co 78 38-159 78 41-139 111 41-267 Chlorophyll a mg/m3 383 103-800 369 119-747 265 60.7-462 Calcium mg/L 22.7 17.8-27.2 22.7 16.5-26.7 22.4 16.5-27.9 Chloride mg/L 16.1 3.9-22.6 14.8 4.6-22.9 15.6 4.2-22.5 Chloride mg/L 16.1 3.9-22. 6 14.8 4.6-22.9 15.6 4.2-22.5 Environmental Research and Design, Inc., March, 2005. 

### An extremely high degree of variability was obs erved in measured concentrations of all nitrogen species, particularly for ammonia and particulate nitrogen. Variability in measured values for ammonia cover approximately two orders of magnitude at the three monitoring sites, with approximately one order of magnitude between minimum and maximum values for particulate nitrogen at the three sites. In general, concentrations of measured nitrogen species were relatively similar between the three sites. Measured TN concentrations, whichDRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 9 ranged from 3.67-4.08 mg/L between the three monitoring sites, were extremely elevated, with values 2-3 times greater than commonly observed in Central Florida lakes (ERD, 2005).

Particulate nitrogen was clearly the most dominant nitrogen species observed at each of the three sites, comprising 64-71 percent of the nitrogen present. The second most dominant species was dissolved organic nitrogen, which comprised 22-32 percent of the total nitrogen measured at the three sites. Substantially sm aller contributions were observed for ammonia (4-6% of total nitrogen) and NOx (1% of total nitrogen) (ERD, 2005).
Mean total phosphorus concentrations, which ranged from 0.42-0.48 mg/L at the three sites, were extremely high in value, compared with concentrations typically observed in Central Florida lakes. Particulate phosphorus appeared to be the dominant phosphorus species observed at each of the three monitoring sites, comprising 68-74 percent of the total phosphorus measured at each site. Soluble Reactive Phosphorus (SRP) was the second most dominant phosphorus species measured in Lake Hancock, comprising 21-28 percent of the total phosphorus measured. Dissolved organic phosphorus contributed approximately 4-5 percent of the total phosphorus measured at each site (ERD, 2005).

Extremely elevated concentrations of chlorophyll a were observed in Lake Hancock, with measured values approximately 10 times greater than commonly observed in urban lakes. Mean chlorophyll a concentrations measured were to be 3-4 times greater than concentrations commonly measured in hypereutrophic lakes such as Lake Apopka and Lake Jessup. Chlorophyll a concentrations were also highly variable at each of the three monitoring sites, with a factor of approximately 8 between minimum and maximum chlorophyll a values measured at each site (ERD, 2005).
As a note, hurricanes Charley, Frances, and Jeanne occurred during the 2004 season in this region of the state of Florida which increased the flushing and dilution to Lake Hancock from tributary inflows.


### 1.4 Lake Hancock Background Information

The Lake Hancock watershed is located within west-central Polk County near the geographic center of peninsular Florida. Polk County is part of the highland area that trends along the north-south axis of peninsular Florida. Within the county there are three ridges separated by relatively flat lowland areas. The Lake Hancock watershed occupies the area between the Lakeland Ridge on the western boundary and Winter Haven Ridge along the eastern boundary (BCI Engineers and Scientists, Inc., 2005). Significant portions of the watershed have been mined for phosphate ore creating numerous spoil piles, clay settling area embankments, and water filled depressions and lakes.
Lake Hancock receives inflow from primarily th ree major tributaries. Middle and Upper Saddle Creek originate to the north and east of the City of Lakeland and generally flow south through a swampy depression before turning into a creek and entering into the north shore of the lake. Lake Lena Run originates in Auburndale and enters Lake Hancock on the northeast side. Banana Lake, located about 1-mile northwest of Highland City, discharges into the Banana Lake Overflow Canal that enters the west side of the Lake. These three tributaries account for approximately 81 percent of the Lake Hancock watershed. The Eagle Lake system located below Lake Lena Run is a minor tributary that originates in the Eagle Lake area and enters Lake Hancock on the southeast side. Remaining areas of the watershed are contiguous to the lake.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 10 Climate in the Lake Hancock Basin is subtropi cal with humid, rainy summers, and dry mild winters. Average monthly temperatures r ange from 61°F in January to 82°F in July and August. About half of the annual rainfall occurs during the summer months of June through September. There has been an extended period of below normal rainfall in the Lake Hancock area and in central Florida generally since 1960.

The Lake Hancock Watershed is underlain by a layer of sand, clay, and limestone, ranging in thickness from about 100 to 400 feet. Under the surficial layer is several thousand feet of limestone and dolomite. The formations comp rising the watershed (Hammett, Snell, Joyner; USGS 1981) can be divided into three hydrogeologic units: (1) the surficial aquifer, (2) the secondary artesian aquifers and confining beds, and (3) the Floridian aquifer. The surficial aquifer is composed of sand, sandy clay, and pebble phosphate deposits, which in Polk County have been strip mined extensively. The thickness of this unit varies between 20 and 130 feet. The secondary artesian aquifers and confining beds are composed of clay, dolomite, and limestone of the Hawthorn Formation and Tampa Limestone. The thickness of this unit varies between 50 and 150 feet.

The Floridian aquifer consists of limestone and dolomite of the Suwannee Limestone, Ocala Limestone, and Avon Park Limestone. Drilling logs indicate that zones within the limestone and dolomite contain numerous caviti es and honeycomb features that have resulted from dissolution of the carbonate rock by circulating ground water. Weaknesses in the geologic structure caused by dissolution are responsible for sinkhole collapses. In 1976, Ardaman and Associates, Inc., reported that between 1956 and 1975 more than 20 sinkhole collapses had occurred within two miles of Lake Hancock.
Ground water in the surficial and the secondary artesian aquifers typically flow from the ridge areas to the streams and lakes of the lowland areas. However, the lowering of the Florida aquifer due to ground water withdrawals has created a downward movement of the surficial water into the secondary artesian in the area of Lake Hancock and the upper Peace River.

A muck layer ranging in thickness from 1 to 4 feet covers the bottom of the lake. Underlying the muck are surficial deposits ranging from 9 to 17 feet in thickness which reside on top of the Bone Valley Formation containing phosphatic sands, gravels, and clays (Patton, 1980). Below the Bone Valley formation are Hawthorne limestones that have been dissolutioned by lateral movement of water to form the lake (BCI Engineers and Scientists, Inc., 2005).

Mining for phosphate in the vicinity of Lake Hancock began between 1941 and 1952. No mining in the vicinity of Lake Hancock is evident in a 1941 aerial photograph of the Lake. By 1952, aerial photographs indicate some areas approximately one mile to the northeast of the lake were being mined. Areas to the south of the lake showed mining activity by 1958. These areas were ultimately converted to clay settling areas. The 1968 aerials show active mining along the majority of the east side of the lake. Most of these mined areas have been reclaimed (BCI Engineers and Scientists, Inc., 2005).


### 1.5 TMDL Background Information

The TMDL report for Lake Hancock and Lower Saddle Creek is part of the implementation of the Department’s watershed management approach for restoring and protecting water resources and addressing Total Maximum Daily Load (TMDL) Program requirements. The watershed approach, which is implemented using a cyclical management process that rotates through the state’s fifty-two river basins over a five-year cycle, provides a framework forDRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 11 implementing the requirements of the 1972 federal Clean Water Act and the 1999 Florida Watershed Restoration Act (Chapter 99-223, Laws of Florida).

A TMDL represents the maximum amount of a given pollutant that a waterbody can assimilate and still meet the waterbody’s designated uses. A waterbody that does not meet its designated uses is defined as impaired. TMDLs must be developed and implemented for each of the state’s impaired waters, unless t he impairment is documented to be a naturally occurring condition that cannot be abated by a TMDL or unless a management plan already in place is expected to correct the problem.

The development and implementation of a Basin Management Action Plan, or BMAP, to reduce the amount of pollutants that caused the impairment will follow this TMDL Report. These activities will depend heavily on the active participation of the Southwest Florida Water Management District (SWFWMD), Polk County, local governments, local businesses, and other stakeholders. The Department will work with these organizations and individuals to undertake or continue reductions in the discharge of pollutants and achieve the established TMDLs for Lake Hancock and Lower Saddle Creek.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 12 

# Chapter 2: STATEMENT OF WATER QUALITY
PROBLEM

2.1 Statutory Requirement s and Rulemaking History

Section 303(d) of the federal Clean Water Act requires states to submit to the EPA a list of surface waters that do not meet applicable water quality standards (impaired waters) and establish a TMDL for each pollutant causing the impairment of the listed waters on a schedule. The Department has developed such lists, commonly referred to as 303(d) lists, since 1992. The list of impaired waters in each basin, referred to as the Verified List, is also required by the Florid Watershed Restoration Act (Subsection 403.067[4)] Florida Statutes [F.S.]), and the state’s 303(d) list is amended annually to include basin updates.

Florida’s 1998 303(d) list included 52 waterbodies in the Peace River Planning Unit with 11 of those waterbodies in the Lake Hancock Basin. However, the FWRA (Section 403.067, F.S.) stated that all previous Florida 303(d) lists were for planning purposes only and directed the Department to develop, and adopt by rule, a new science-based methodology to identify impaired waters. In April 2001, the Envir onmental Regulation Commission adopted the new methodology as Chapter 62-303, F.A.C., (Identification of Impaired Surface Waters Rule, or IWR).


### 2.2 Information on Verified Impairment

The Department used the IWR methodology to assess water quality in Lake Hancock and Lower Saddle Creek, and both the lake and the creek were verified impaired for nutrients and dissolved oxygen (DO). Lake Hancock was verified as impaired in 2003 for nutrients based on an annual average Trophic State Index (TSI) value of 83.5, which exceeded the IWR threshold value of 60 during the verification period (the Verified Period for the Group 3 basins is from January 1, 1997 to June 30, 2004). The median values for Total Nitrogen (TN), Total Phosphorus (TP), and biochemical oxygen demand (BOD) for the lake for the verified period were 4.46, 0.49, and 9.9 mg/L, respectively, which are significantly higher than the 70 th 

### percentile for Florida lakes (see Table 2.1 ).

Table 2.1 Screening Level Values (70th percentile) Based on STORET Data from 1979 to 1987

Waterbody Type BOD 5 Day (mg/L) Total Nitrogen (mg/L) Total Phosphorus (mg/L)

Stream 2.0 1.6 .22

Lake 2.9 1.7 .11 Estuary 2.1 1.0 .19 Source: Friedemann, F., and Hand, J., July 1989.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 13 The TSI is calculated based on concentrations of TP, TN, and chlorophyll a as follows:

TSI Formula

CHLA TSI 

### = 16.8 + 14.4 * LN(Chl a ) Chlorophyll a in μg/L TN TSI 

### = 56 + 19.8 * LN(N) Nitrogen in mg/L TN2 TSI 

### = 10 * [5.96 + 2.15 * LN(N + 0.0001)] Phosphorus in mg/L TPTSI = 18.6 * LN(P * 1000) – 18.4 TP2 TSI 

### = 10 * [2.36 * LN(P * 1000) – 2.38]

If N/P > 30, then NUTR TSI 

### = TP2 TSI 

### If N/P < 10, then NUTR TSI 

### = TN2 TSI 

### if

10< N/P < 30, then NUTR TSI 

### = (TP TSI 

### + TN TSI 

### )/2

TSI = (CHLA TSI 

### + NUTR TSI 

### )/2 Note: TSI has no units

The lake is listed as impaired for DO because, from 1997 to 2004, more than 10 percent of the DO results did not meet the freshwater DO criterion of 5 mg/L. Following the IWR methodology, there were 27 DO exceedances out of 140 samples (19.3 percent exceedance rate).

Lower Saddle Creek was verified as impaired for nutrients based on elevated seasonal and annual average chlorophyll a values that exceeded the IWR listing threshold of 20 μ g/L for freshwater streams. Annual average chlorophyll a values for the Verified Period (years 1997 to 2003) were 107, 89.1, 141.1, 73.5, 102.6, 93.2, and 163.5 μ /g/L, respectively. The median TN, TP, and BOD values for the creek for the verified period were 2.40, 0.40, and 6.5 mg/L, respectively. The creek was verified as impaired for DO because, from 1997 to 2004, more than 10 percent of the DO results did not meet the freshwater DO criterion of 5 mg/L. Following the IWR methodology, there were 46 DO exceedances out of 130 samples (35.4 percent exceedance rate).

For modeling purposes, the analyses of the eutrophication-related data for Lake Hancock used “all” of the available data from 1984 – 2004 for which records of TP, TN, and chlorophyll

a were sufficient to calculate seasonal annual average conditions. However, to calculate the TSI for a given year under the IWR, there must be at least one sample of TN, TP, and chlorophyll a taken at the same time period in each season of the year. The absence of data from all four seasons for many years in t he planning and verified periods resulted in 2003 as the only year with sufficient data to calculate a TSI for Lake Hancock for assessing impairment following the IWR methodology.

Figure 2.1 displays annual average TSI values for all data from 1984 to 2004 (includes Lakewatch data) and the IWR verified period TSI value from 2003 (does not include Lakewatch data). Additionally, as the verified period ends in June of 2004, annual averages were not calculated for 2004 during the IWR assessment for the Lake Hancock Basin, but are displayed in Figure 2.1 for review. In 2003, the seasonal annual average TSI value of 83.5 exceeded the IWR threshold value of 60. Exceeding 60 in any one year of the verified period is sufficient in identifying a lake as being impaired for nutrients. Annual average color values for the verified period for the lake were 53.3 (1997), 73.3 (1998), 240 (1999), 108.3 (2002), and 100.3 (2003). The annual average color value for years in the verified period was 115.04.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 14 Monthly and annual average TN results for Lake Hancock from 1992 to 2004 are displayed in Figures 2.2 and 2.3

, respectively. Monthly and annual average TP results from 1992 to 2004 are displayed in Figures 2.4 and 2.5

. Monthly and annual average chlorophyll a results from 1992 to 2004 are displayed in Figures 2.6 and 2.7

. Monthly and annual average DO results from 1992 to 2004 are displayed in Figures 2.8 and 2.9

. Monthly and annual average TN results for Lower Saddle Creek from 1992 to 2004 are displayed in Figures 2.10 and 2.11

, respectively. Individual station and annual average TP results from 1992 to 2004 are displayed in Figures 2.12 and 2.13. Monthly and annual average chlorophyll a results from 1992 to 2004 are displayed in Figures 2.14 and 2.15 . Monthly and annual average DO results for Lower Saddle Creek from 1992 to 2004 are displayed in Figures 2.16 and 2.17

.
Values from all stations for TN for Lake Hancock from 1992 to 2004 were typically highest during the months of February, May, August, and November. Values for TP were highest during the months of February, May, and November. Values for chlorophyll a were highest during the months of February, May, and August. Values for DO from 1992 to 2003 were typically lowest during the months of May and August.

For Lower Saddle Creek from 1992 to 2004, TN, TP and chlorophyll a values were consistently high through-out all months/seasons for the period of record. However, values from all stations for TN appeared to typically be highest during the months of February, July, August, and October. Values for TP were highest during the months of April, August, October and November. Values for chlorophyll a from 1995 to 2004 were highest during the months of April, August, and November. Values for DO from 1992 to 2004 were lowest during the months of April, May, July, August, and October.

The months of August and November appear to show the strongest relationship in terms of consistently having high monthly values for TN, TP, and chlorophyll a between the lake and creek. The months of May and August appear to show the strongest relationship in regard to low DO values for the lake and the creek. The fluctuations in water quality values appear to be quite variable between the months and seasons for the lake and the creek.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 15 Lake Hancock - WBID 1623L Trophic State Index (TSI) Annual Mean Results 1984-2004

0 20 40 60 80 100 120

1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 YearTSI

All Results-WBID 1623L IWR Results-WBID 1623L



### Figure 2.1 TSI Results for Lake Hancock Calculated from Annual Average Concentrations of TP, TN, and Chlorophyll a from 1984 to 2004

Lake Hancock - WBID 1623L Total Nitrogen Results 1992-2004

0 2 4 6 8 10 12 14

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 DateTN (mg/L)

21 FLPOLKHANCOCK A 21 FLPOLKHANCOCK B 21 FLPOLKHANCOCK C 21 FLPOLKHANCOCK D 21 FLPOLKHANCOCK1 21 FLPOLKHANCOCK H 2-62 21 FLSWFDSTA01 92 21 FLTPA 25020276



### Figure 2.2 Total Nitrogen Monthly Results for Lake Hancock from 1992 to 2004DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 16 Lake Hancock - WBID 1623L Total Nitrogen Annual Mean Results 1992-2004

0 1 2 3 4 5 6 7 8 9 10

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
YearTN (mg/L)

All Stations-WBID 1623L


### Figure 2.3 Total Nitrogen Annual Mean Results for Lake Hancock from 1992 to 2004

Lake Hancock - WBID 1623L Total Phosphorus Results 1992-2004

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 DateTP (mg/L)

21 FLPOLKHANCOCK A 21 FLPOLKHANCOCK B 21 FLPOLKHANCOCK C 21 FLPOLKHANCOCK D 21 FLPOLKHANCOCK1 21 FLPOLKHANCOCK H 2-62 21 FLSWFDSTA01 92 21 FLTPA 25020276 Figure 

### 2.4 Total Phosphorus Monthly Results for Lake Hancock from 1992 to 2004DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 17 Lake Hancock - WBID 1623L Total Phosphorus Annual Mean Results 1992-2004

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
YearTP (mg/L)

All Stations-WBID 1623L


### Figure 2.5 Total Phosphorus Annual Mean Results for Lake Hancock from 1992 to 2004

Lake Hancock - WBID 1623L Chlorophyll a Results 1992-2004

0 50 100 150 200 250 300 350 400 450 500

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 DateChorophylla(μg/L)

21 FLPOLKHANCOCK A 21 FLPOLKHANCOCK B 21 FLPOLKHANCOCK C 21 FLPOLKHANCOCK D 21 FLPOLKHANCOCK 9-62 21 FLPOLKHANCOCK1 21 FLSWFDSTA01 92 21 FLTPA 25020276 Figure 

### 2.6 Chlorophyll a Monthly Results for Lake Hancock from 1992 to 2004DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 18 Lake Hancock - WBID 1623L Chlorophyll a Annual Mean Results 1992-2004

0 50 100 150 200 250

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 YearChlorophylla(g/L)

All Stations-WBID 1623L



### Figure 2.7 Chlorophyll a Annual Mean Results for Lake Hancock from 1992 to 2004

Lake Hancock - WBID 1623L Dissolved Oxygen Results 1992-2004

0 2 4 6 8 10 12 14 16 18

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 DateDO (mg/L)

21 FLPOLKHANCOCK A 21 FLPOLKHANCOCK B 21 FLPOLKHANCOCK C 21 FLPOLKHANCOCK D 21 FLPOLKHANCOCK1 21 FLPOLKHANCOCK H-9-63 21 FLSWFDSTA01 92 21 FLTPA 25020276 DO Freshwater Criterion



### Figure 2.8 Dissolved Oxygen Monthly Results for Lake Hancock from 1992 to 2004DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 19 Lake Hancock - WBID 1623L Dissolved Oxygen Annual Mean Results 1992-2004

0 2 4 6 8 10 12 14

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 YearDO (mg/L)

All Stations-WBID 1623L DO Freshwater Criterion



### Figure 2.9 Dissolved Oxygen Annual Mean Results for Lake Hancock from 1992 to 2004

Lower Saddle Creek - WBID 1623K Total Nitrogen Results 1992-2004

0 1 2 3 4 5 6 7 8 9 10

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04
DateTN (mg/L)

21FLPOLKP.C. CANAL9 21FLSWFDFLO 37 72 0 21FLSWFDFLO0038 112WRD 02294491



### Figure 2.10 Total Nitrogen Monthly Results for Lower Saddle Creek from 1992 to 2004DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 20 Lower Saddle Creek - WBID 1623K Total Nitrogen Annual Mean Results 1992-2004

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0

1992 1993 1994 1995 1996 1998 1999 2000 2001 2002 2003 2004 YearTN (mg/L)

All Stations-WBID 1623K



### Figure 2.11 Total Nitrogen Annual Mean Results for Lower Saddle Creek from 1992 to 2004

Lower Saddle Creek - WBID 1623K Total Phosphorus Results 1992-2004

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 DateTP (mg/L)

21FLPOLKP.C. CANAL9 21FLSWFDFLO 37 72 0 21FLSWFDFLO0038 21FLTPA 27552158149358 112WRD 02294491



### Figure 2.12 Total Phosphorus Monthly Results for Lower Saddle Creek from 1992 to 2004DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 21 Lower Saddle Creek - WBID 1623K Total Phosphorus Annual Mean Results 1992-2004

0.00 0.25 0.50 0.75 1.00 1.25 1.50 1.75 2.00 2.25 2.50 2.75 3.00

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 YearTP (mg/L)

All Stations-WBID 1623K



### Figure 2.13 Total Phosphorus Annual Mean Results for Lower Saddle Creek from 1992 to 2004

Lower Saddle Creek - WBID 1623K

Chlorophyll a Results 1995-2004

0 20 40 60 80 100 120 140 160 180

Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 DateChlorophylla(g/L)

21FLPOLKP.C. CANAL9 21FLSWFDFLO 37 72 0 21FLTPA 27552158149358



### Figure 2.14 Chlorophyll a Monthly Results for Lower Saddle Creek from 1995 to 2004DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 22 Lower Saddle Creek - WBID 1623K Chlorophyll a Annual Mean Results 1995-2004

0 20 40 60 80 100 120 140 160 180 200

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 YearChlorophylla(g/L)

All Stations-WBID 1623K



### Figure 2.15 Chlorophyll a Annual Mean Results for Lower Saddle Creek from 1995 to 2004

Lower Saddle Creek - WBID 1623K Dissolved Oxygen Results 1992-2004

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 DateDO (mg/L)

21FLPOLKP.C. CANAL9 21FLSWFDFLO 37 72 0 21FLSWFDFLO0038 21FLTPA 27552158149358 112WRD 02294491 DO Freshwater Criterion



### Figure 2.16 Dissolved Oxygen Monthly Results for Lower Saddle Creek from 1992 to 2004DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 23 Lower Saddle Creek - WBID 1623K Dissolved Oxygen Annual Mean Results 1992-2004

0 1 2 3 4 5 6 7 8 9 10 11 12

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 YearDO (mg/L)

All Stations-WBID 1623K DO Freshwater Criterion


### Figure 2.17 Dissolved Oxygen Annual Mean Results for Lower Saddle Creek from 1992 to 2004

Table 2.2 provides summary statistics for the lake and creek for TN, TP, chlorophyll a , and DO from 1992 to 2004. Individual water quality measurements for TN, TP, chlorophyll a , and DO used in the assessment are provided in Appendix B

.

Table 2.2 Water Quality Summary Statistics for TN, TP, Chlorophyll a , and DO from 1992 to 2004 for Lake Hancock (WBID 1623L) and Lower Saddle Creek (WBID1623K)

Waterbody Water Variable # of Samples Minimum Mean Median Maximum

Lake Hancock Total Nitrogen (mg/L) 134 1.19 4.57 4.40 12.03

Lake Hancock Total Phosphorus (mg/L) 135 0.04 0.52 0.49 1.01

Lake Hancock Chlorophyll a ( μ g/L) 77 16.02 175.15 148 558.00

Lake Hancock Dissolved Oxygen (mg/L) 140 0.38 8.26 8.43 15.70

Lower Saddle Cr

. Total Nitrogen (mg/L) 75 0.39 2.95 2.50 11.02

Lower Saddle Cr. Total Phosphorus (mg/L) 134 0.01 0.63 0.45 10.50

Lower Saddle Cr. Chlorophyll a ( μ g/L) 111 1.00 101.18 79.30 612.00

Lower Saddle Cr. Dissolved Oxygen (mg/L) 130 0.31 6.08 6.26 15.56DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 24 As part of the listing process, the Department attempts to identify the limiting nutrient or nutrients for the impaired waterbody. The limit ing nutrient, generally nitrogen or phosphorus, is defined as the nutrient that limits plant growth when it is not available in sufficient quantities. A limiting nutrient is a chemical that is necessary for plant growth, but available in quantities smaller than those needed for algae, represented by chlorophyll a , and macrophytes to grow. Once the limiting nutrient in a waterbody is exhausted, algae stop growing. If more of the limiting nutrient is added, larger algal populations will result until nutrients or other environmental factors again limit their gr owth. In Florida waterbodies, nitrogen and phosphorus are most often the limiting nutrients

The following method is used to identify the limiting nutrient(s) in streams and lakes:

• The ratios of TN to TP are calculated for each paired value of TN and TP (per sampling event) collected during the verified period. If a waterbody segment TN or TP median values exceed the appropriate screening levels, the nutrient exceeding the screening level may be identified as a potential pollutant causing impairment. The median values are then compared with the screening levels for the appropriate waterbody type. The screening levels represent the 70th percentile value of data collected from streams, lakes, or estuaries in Florida (see Table 2.1 ).

• The individual ratios over the entire verified period (i.e., January 1997 to June 2004) are evaluated to determine the limiting nutrient(s). If all the sampling event ratios are less than 10, nitrogen is identified as the limiting nutrient, and if all the ratios are greater than 30, phosphorus is identified as the limiting nutrient. Both nitrogen and phosphorus are identified as limiting nutrients if the ratios are between 10 and 30. For Lake Hancock and Lower Saddle Creek the median TN/TP ratios are 9.49 and 7.22, respectively, for the verified period, suggesting that nitrogen is the limiting nutrient in the lake and creek.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 25 

# Chapter 3. DESCRIPTION OF APPLICABLE WATER QUALITY STANDARDS AND TARGETS

3.1 Classificat ion of the Waterbody and Criteria Applicable to the TMDL

Florida’s surface water is protected for five designated use classifications, as follows:

Class I Potable water supplies Class II Shellfish propagation or harvestingClass III Recreation, propagation, and maintenance of a healthy, wellbalanced population of fish and wildlife Class IV Agricultural water supplies Class V Navigation, utility, and industrial use (there are no state waters currently in this class)

Lake Hancock and Lower Saddle Creek are classified as Class III freshwater waterbodies, with a designated use of recreation, propagation and maintenance of a healthy, well-balanced population of fish and wildlife. The Class III water quality criterion applicable to the observed impairments for Lake Hancock and Lower Saddle Creek are the state of Florida’s narrative nutrient criterion [Rule 62-302.530(48)(b), FAC] and dissolved oxygen criterion [Rule 62- 302.530(31), F.A.C].


### 3.2 Dissolved Oxygen Crit erion for Lakes and Streams

The Class III freshwater criterion for dissolved oxygen (DO) for lakes and streams, established by Subsection 62-302.530(31), F.A.C., states that DO shall not be less than 5.0 mg/L and that normal daily and seasonal fluctuations above these levels shall be maintained.

As required by the IWR, the Department must identify the pollutants causing or contributing to DO impairment. If a waterbody segment has a sufficient number of DO exceedances for placement on the Verified List and nutrients is on the Verified List, based on exceedances of the IWR TSI or chlorophyll a thresholds, then “nutrients” is identified as a pollutant contributing to DO exceedances. The Department also applies the following analysis to identify the pollutant(s) contributing to DO exceedances:

• The waterbody segment median values for biochemical oxygen demand (BOD), total nitrogen (TN), and total phosphorus (TP) are determined for the verified period (i.e., January 1997 to June 2004).

• The median values are then compared with the screening levels for the appropriate waterbody type. The screening levels represent the 70th percentile value of data collected from streams, lakes, or estuaries in Florida (Table 2.2)

. • If a waterbody segment median BOD value exceeds the screening level, BOD is identified as a pollutant contributing to DO exceedances.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 26 • If a waterbody segment TN or TP median values exceed the appropriate screening levels, and there are insufficient data to assess nutrients using the IWR TSI or chlorophyll a thresholds, the nutrient exceeding the screening level may be identified as a pollutant contributing to the exceedances. As noted in Chapter 2, Section 2.2, the median values for TN, TP, and BOD for the lake for the verified period exceeded the 70 th 

### percentile for Florida lakes.

For Lake Hancock and Lower Saddle Creek, low DO concentrations appear to be related to excessive nutrient loadings. During the verified period, monthly and annual average chlorophyll a concentrations for the lake and the creek were well above the IWR’s thresholds for nutrient impairment.

In addition to causing excessive growth of algae, nutrient enrichment of a waterbody can lead to widely varying DO levels and low DO concentrations in the water column. Depressed DO concentrations may be caused by several factors, including the decay of oxygen demanding waste from point and non-point sources, conversion of ammonia to nitrate in the nitrification process (where oxygen is consumed by aerobic nitrifying bacteria), macrophyte respiration, excessive epiphyte or floating macrophyte growth blocking light to submerged aquatic vegetation, and sediment oxygen demand (SOD). Nutrients may also influence DO levels indirectly. Algal populations can increase rapidly if nutrients are available resulting in the production of oxygen from the process of photosynthesis during daylight hours. Algal respiration or consumption of oxygen from the water column at night may also result in large diurnal fluctuations of DO in the water column. A fraction of any increased algal biomass may also become part of the organic material that will be broken down by microbes or settle to the bottom. Processes that consume oxygen from the water column such as microbial breakdown of organic material and SOD are fairly constant over the short term.

Although nitrogen appears to be the limiting nutrient for the lake and the creek, reductions in TN and TP loadings would be expected to result in decreases in chlorophyll a

. Reductions in TN and TP loadings to the lake are also expected to result in additional benefits for other parameters contributing to the impairment including DO and biochemical oxygen demand (BOD). The reduction in nitrogen and phosphorus loads should result in lower algal biomass levels in the water column, and lower algal biomass levels will result in smaller diurnal fluctuations in DO and less algal-based total suspended solids and reduced BOD

. Water quality in Lower Saddle Creek is directly influenced by the water quality in Lake Hancock. As such, the high nutrient values in the lake are linked to the excessive algal growth that led to the lake and the creek being impaired for low DO. As a result of this direct influence, it is anticipated that achieving the TMDL for nutrients in Lake Hancock will result in achieving water quality standards in Lower Saddle Creek. Therefore, the DO impairment for the lake and the DO and nutrient impairment for the creek are addressed by the nutrient TMDL for Lake Hancock.


### 3.3 Interpretation of the Narrative Nutr ient Criteria for Lakes and Streams

Florida’s nutrient criterion is narrative only — nutrient concentrations of a body of water shall not be altered so as to cause an imbalance in natural populations of aquatic flora or fauna. Accordingly, a nutrient-related target was needed to represent levels at which an imbalance in flora or fauna is expected to occur. While the IWR provides a threshold for nutrient impairment for lakes based on annual average TSI levels, these thresholds are not standards and are not required to be used as the nutrient-related water quality target for TMDLs. InDRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 27 recognition that the IWR thresholds were developed using statewide average conditions, the IWR (Subsection 62-303.450, F.A.C.) specifically allows the use of alternative, site-specific thresholds that more accurately reflect conditions beyond which an imbalance in flora or fauna occurs in the waterbody.
The TSI originally developed by R. E. Carlson (1977) was calculated based on Secchi depth, chlorophyll concentration, and total phosphorus concentration and was used to describe a lake’s trophic state. Carlson’s TSI was developed based on the assumption that the lakes were all phosphorus limited. In Florida, because the local geology produced a phosphorus rich soil, nitrogen can be the sole or co-limiting factor for phytoplankton in some lakes. In addition, because of the existence of dark-water lakes in the state, using Secchi depth as an index to represent lake trophic state can produce misleading results.
Therefore, the TSI was revised to be based on total nitrogen, total phosphorus, and chlorophyll a concentrations. This revised calculation for TSI now contains a TN -TSI, TP -TSI, and chlorophyll a -TSI. As a result, there are three different ways of calculating a final in-lake TSI. If the TN to TP ratio is equal to or greater than 30, the lake is considered phosphorus limited and the final TSI is the average of the TP -TSI and the chlorophyll a - TSI. If the TN to TP ratio is 10 or less, the lake is considered nitrogen limited and the final TSI is the average of the TN -TSI and the chlorophyll a -TSI. If the TN to TP ratio is between 10 and 30, the lake is considered co-limited and the final TSI is the result of averaging the chlorophyll a -TSI with the average of the TN and TP TSI’s.

The Florida-specific TSI for Lakes was determined based on the analysis of data from 313 Florida lakes. The index was adjusted so that a chlorophyll a concentration of 20 μ g/L was equal to a chlorophyll a -TSI value of 60. The final TSI for any lake may be higher or lower than 60 depending on the TN -TSI and the TP -TSI values. A TSI of 60 was then set as the threshold for nutrient impairment for most lakes (for those with a color higher than 40 platinum cobalt units) because, generally, the phytoplankt on may switch to communities dominated by blue-green algae at chlorophyll a levels above 20 μ g/L. These blue-green algae are often an unfavorable food source to zooplankton and many other aquatic animals. Some blue-green algae may even produce toxins, which could be harmful to fish and other animals. In addition, excessive growth of phytoplankton and t he subsequent death of these algae may consume large quantities of dissolved oxygen and result in anaerobic condition in lakes, which makes conditions in the impacted lake unfavorable for fish and other wildlife. All of these processes may negatively impact the health and balance of native fauna and flora.

Because of the amazing diversity and productivity of Florida lakes, some lakes have a natural background TSI that is different from 60. In recognition of this natural variation, the IWR allows for the use of a lower TSI (40) in very clear lakes, a higher TSI if paleolimnological data indicate the lake was naturally above 60, and the development of site-specific thresholds that better represent the levels at which nutrient impairment occurs. For the Lake Hancock and Lower Saddle Creek TMDLs, the Department applied the Watershed Assessment Model (WAM) (Soil and Water Engineering Technology, Inc., 2005) and the BATHTUB model (Quantitative Environmental Analysis, LLC, 2005) to simulate water quality discharges and eutrophication processes to determine the appr opriate nutrient loadings. The WAM model was used to estimate the natural background TSI by setting land uses to a mixture of natural land cover. The loadings were then input to the BATHTUB lake model to calculate a natural background TSI value. Once the natural background TSI was determined, then an increase of 5 TSI units above natural background was used as the water quality target for the TMDL. The estimated natural background TSI for Lake Hancock is 69.4, with a target TSI of 74.4.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 28 3.3.1 Criteria Definitions

Chlorophyll a Chlorophyll is a green pigment found in plants and is an essential component in the process of converting light energy into chemical energy. Chlorophyll is capable of channeling the energy of sunlight into chemical energy through the process of photosynthesis. In photosynthesis, the energy absorbed by chlorophyll transforms carbon dioxide (CO 2 

### ) and water (H 2 

### O) into carbohydrates and oxygen (O 2 

### ). The chemical energy stored by photosynthesis in carbohydrates drives biochemical reactions in nearly all living organisms. Thus, chlorophyll is at the center of the photosynthetic oxidation-reduction reaction between carbon dioxide and water.
There are several types of chlorophyll; how ever, the predominant form is chlorophyll a . The measurement of chlorophyll a in a water sample is a useful indicator of phytoplankton biomass, especially when used in conjunction wi th analysis concerning algal growth potential and species abundance. The greater the abundance of chlorophyll a , typically the greater the abundance of algae. Algae are the primary producers in the aquatic food web, and thus are very important in characterizing the productivity of lakes and streams. As noted earlier, chlorophyll a measurements are also used to estimate the trophic conditions of lakes and lentic waters.

Biochemical Oxygen Demand (BOD) BOD values are a measure of food for natur ally occurring microorganisms. When food is introduced, naturally occurring microorganisms begin to multiply rapidly at an exponential rate, resulting in the reduction of dissolved oxygen in the water. After all of the food is consumed, they die and become food for protozoa, which in turn die off and become food for rotifers and crustaceans. BOD provides a quantitative measure of the amount of oxygen required to maintain the growth and activities of the microbial organisms responsible for the aerobic digestion of organic and putrescible matter. High BOD demand is a major contributor to DO depletion and is normally indicative of poor water quality.

Dissolved Oxygen (DO) Dissolved oxygen is an essential component in the aquatic environment. Like terrestrial species, fish and other aquatic organisms need oxy gen to survive. As an example, for fish, as water moves through the gills, microscopic bubbles of oxygen gas in the water (called dissolved oxygen) are transferred from the water to the blood stream. Like any other gas diffusion process, the transfer of DO is efficient only above certain concentrations. DO is also important for many chemical reactions that are important for a healthy functioning waterbody. DO is produced during photosynthesis and consumed during respiration and decomposition. DO is also produced where water and air meet (i.e., diffusion of air molecules into the water from wind action, surface water turbulence, inflowing streams etc.)

Nitrogen Total as N (TN) Total nitrogen is the combined measurement of nitrate (NO 3 - 

### ), nitrite (NO 2 - 

### ), ammonia (NH 3 

### + NH 4 + 

### ), and organic nitrogen (NH 2 

### ) found in water. Nitrogen compounds function as important nutrients to many aquatic organisms and are essent ial to the chemical processes that exist between land, air, and water. The most readily bioavailable forms of nitrogen are ammonia and nitrate. These compounds, in conjunction with other nutrients, serve as an important base for primary productivity.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 29 The major source of excessive amounts of nitrogen in surface water are the effluent from municipal treatment plants and runoff from agric ultural sites. When nutrient concentrations consistently exceed natural levels, the resulting nutrient imbalance can cause undesirable changes in a waterbody’s biological comm unity and drive an aquatic system into an accelerated rate of eutrophication. Usually, the eutrophication process is observed as a change in the structure of the algal community and includes severe algal blooms that may cover large areas for extended periods. Lar ge algal blooms are generally followed by a depletion in dissolved oxygen concentrations as a result of algal decomposition.

Phosphorus Total as P (TP) Phosphorus is one of the primary nutrients that regulates algal and macrophyte growth in natural waters, particularly in fresh water. Phosphate, the form in which almost all phosphorus is found in the water column, can enter the aquatic environment in a number of ways. Natural processes transport phosphate to water through atmospheric deposition, ground water percolation, and terrestrial runoff. Municipal treatment plants, industries, agriculture, and domestic activities also contribute to phosphate loading through direct discharge and natural transport mechanisms. The very high levels of phosphorus in some of Florida’s streams and estuaries are usually caused by phosphate mi ning and fertilizer processing activities.

High phosphorus concentrations are frequently responsible for accelerating the process of eutrophication, or accelerated aging, of a waterbody. Once phosphorus and other important nutrients enter the ecosystem, they are extremely difficult to remove. They become tied up in biomass or deposited in sediments. Nutrients, particularly phosphates, deposited in sediments generally are redistributed to the water column. This type of cycling compounds the difficulty of halting the eutrophication process.


### 3.4 Paleolimnological Information for the Lake Hancock Basin

Paleolimnological methods can be used to identify baseline limnological conditions and to assess anthropogenic changes in lakes that lack historical limnological data. The lack of historical water quality data makes it difficult to document past changes in the trophic status of numerous Florida lakes. The absence of long-term limnological data makes it difficult to document the timing and magnitude of anthropenic changes in most of Florida’s lakes. Thus, paleolimnological studies are very important in yielding information on historical trophic conditions. Three lakes in the modeled Lake Hancock Basin (Hancock, Hollingsworth, and Parker) have historical limnological informat ion available and are briefly discussed below.

Lake Hancock

In 2002, a paleolimnological study of Lake H ancock was performed by the University of Florida (Brenner, Whitmore, Curtis, and Hodell, 2002). Two sediment cores were collected from the lake to evaluate historical trophic state changes in the basin. Sediment diatom assemblages and a variety of nutrient-related variables (density, carbon, nitrogen, phosphorus, and organic matter) were measured. The trophic state was inferred by using models that relate diatom assemblages to water quality variables in Florida lakes. Although age-depth relations for the cores could not be established using radiometric methods, unsupported Lead 210 

### activities in the cores suggested that the upper deposits in the cores accumulated within the last 100 years.

Diatom data from one of the core samples suggest that the lake has been hypereutrophic and there has been no directional change in trophic status over time represented by the top 60DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 30 centimeters (cm) of the core (<100 years). Limnetic total phosphorus and chlorophyll a from the other core sample indicates a shift from eutrophic to hypereutrophic conditions above 28 cm. This suggests that the lake has been hypereutrophic for the last 100 years (or perhaps less) and less productive (eutrophic) beyond that time period, as inferred from sediments that are greater than 100 years old (Brenner, Whitmore, Curtis, and Hodell, 2002). Thus, the results indicate that the trophic state of the lake was historically mesotrophic to eutrophic prior to becoming hypereutrophic. The diatom assemblages and Lead 210 

### dating suggest that this shift probably occurred within the last 100 years, which would temporally correspond with anthropogenic disturbances in the watershed and surrounding air-shed.

However, the authors note that the type of sediment accumulation on the bottom of Lake Hancock makes it a less than ideal archive of paleolimnological information and that diatom assemblages be used only to discern general trends rather than identify specific inference values (i.e., used with caution for this specific lake).

Lake Hollingsworth (Banana Lake Sub-basin)

Similar to most of the lakes located in the Lake Hancock and Saddle Creek basin, Lake Hollingsworth lies in phosphate rich central Florida. In 1899, it was reported that the state’s largest strawberry farm was operating near the lake. In the early 1900s, residential development began on the northwest portion of the lake. The 1920s marked additional changes in land use with the groundbreaking for Florida Southern College and more residents. In the 1950s, citrus groves were prominent in the area, but were steadily being replaced for phosphate mining activities. By the mid-1970s, citrus groves had been replaced by residential and extractive land uses. Today, nearly the entire lake watershed is developed.

The earliest limnological investigations on Lake Hollingsworth suggest that hypereutrophic conditions already existed by the late 1960s (C hew, 1974; Huber et al., 1982). According to Brenner et al., (1995), historical total phosphorus inferences based on diatom analyses from lake-core samples indicated that Lake Hollingsworth was naturally eutrophic. The limnetic phosphorus concentrations increased in the middle of the 20 th 

### century, with very high phosphorus levels occurring between the 1950s and 1970s. The historical perspective provided by the paleolimnological data demonstrates that Lake Hollingsworth was naturally eutrophic, but became hypereutrophic as a consequence of anthropogenic disturbances.
Lake Parker (Lake Parker Sub-basin)

Results from a case study conducted by Brenner, Whitmore, Flannery, and Binford (1993), showed that Lake Parker has displayed statistically significant increases in limnetic total phosphorus and chlorophyll a concentrations since the 1920s. The study evaluated sediment diatom assemblages to infer former water quality. Sediment diatoms are powerful bioindicators of historic and current nutrient concentrations. They are ubiquitous, well preserved, and sensitive to even subtle environm ental shifts (Dixit, et al., 1992)

Although Lake Parker overlies phosphatic deposits, the paleolimnological record from the study indicates that the lake was naturally mesotrophic. Several lines of quantitative evidence (diatom transfer rates and nutrient accumulation rates) suggest progressive increases in total phosphorus and chlorophyll a in the lake between 1920 and 1980. Net accumulation rates of phosphorus have increased more than 10-fold in this century. In addition, there is no evidence of substantial macrophyte presence in the lake (Brenner, Whitmore, Flannery, and Binford, 1993). As a result of human disturbances that affected both the watershed andDRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 31 surrounding airshed, the authors estimate that the lake underwent substantial cultural eutrophication during this time period.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 32 

# Chapter 4: ASSESSMENT OF SOURCES

4.1 Overview of Modeling Process
Lake Hancock is the most downstream lake in the Saddle Creek drainage basin, which makes Lake Hancock the “primary basin” in the model (the term “primary basin” in the Watershed Assessment Model refers to a collection of sub-basins or basins that discharge to a single receiving waterbody).The primary basin setup procedure used to model Lake Hancock is described in detail in “The WAM Watershed Assessment Final Report of the Lake Hancock Basin” (see Appendix H ). The WAM model was then linked to the BATHTUB model. The BATHTUB model simulates nutrients in reservoirs and lakes based on annual average inputs. This model is described in detail in “The BATHTUB Framework for the Lake Hancock Basin, Florida, Final Report” (see Appendix F ).
The external load assessment conducted by the Watershed Assessment Model (WAM) and BATHTUB models was intended to determine the loading characteristics of the various sources of pollutants in the Lake Hancock Basin, including the Lake Hancock and Lower Saddle Creek watersheds (see Figure 4.1 ). Assessing the external load entailed assessing land use patterns, soils, topography, hydrography, point sources, sewer service area coverages, climate, and rainfall to determine the volume, concentration, timing, location, and underlying nature of the point and nonpoint sources of nutrients to the lake.

WAM is a tool that has been shown to be useful in the assessment of watershed-related properties. WAM was developed to allow engineers and planners to assess the water quality of both surface water and ground water. The model simulates the primary physical processes important for watershed hydrologic and pollutant transport. The model assesses the hydrology of the watershed using imbedded models including “Ground Water Loading Effects of Agricultural Management Systems” (GLEAMS; Knisel, 1993), “Everglades Agricultural Area Model” (EAAMod; Botcher et al., 1998; SWET , 1999), and two submodels written specifically for WAM to handle wetland and urban landscapes. Dynamic routing of flows is accomplished through the use of an algorithm that uses a Manning’s flow equation-based technique (Jacobson et al., 1998).
BATHTUB is a U. S. Army Corps of Engineers steady-state model. The model incorporates several empirical equations of nutrient settling and algal growth to predict steady-state nutrient and chlorophyll a concentrations based on waterbody characteristics, hydraulic characteristics, and nutrient loadings. BATHTUB is capable of predicting concentrations of chlorophyll a , total nitrogen (TN), total phosphorus (TP), and transparency in a waterbody under different loading conditions (QEA, LLC, 2005).DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 33 Figure 4.1 Aerial View of the Lake Hancock and Saddle Creek Watershed, Polk County, Florida, 2004DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 34 4.2 Potential Sources of Nutrients in the Lake Hancock and Lower Saddle Creek Watersheds

An important part of the TMDL analysis is the identification of pollutant source categories, source subcategories, or individual sources of the pollutant of concern in the watershed and the amount of pollutant loading contributed by each of these sources. Sources are broadly classified as either “point sources” or “nonpoint sources.” Historically, the term point sources has meant discharges to surface waters that typically have a continuous flow via a discernable, confined, and discrete conveyance, such as a pipe. Domestic and industrial wastewater treatment facilities (WWTFs) are examples of traditional point sources. In contrast, the term “nonpoint sources” was used to describe intermittent, rainfall driven, diffuse sources of pollution associated with everyday human activities, including runoff from urban land uses, agriculture, silviculture, and mini ng; discharges from failing septic systems; and atmospheric deposition.

However, the 1987 amendments to the Clean Water Act redefined certain nonpoint sources of pollution as point sources subject to regulat ion under the EPA’s National Pollutant Discharge Elimination Program (NPDES). These nonpoint sources included certain urban stormwater discharges, including those from local governmen t master drainage systems, construction sites over five acres, and a wide variety of industries (see Appendix A for background information on the federal and state stormwater programs).

To be consistent with Clean Water Act definitions, the term “point source” will be used to describe traditional point sources (such as domestic and industrial wastewater discharges) and stormwater systems requiring an NPDES stor mwater permit when allocating pollutant load reductions required by a TMDL (see Section 6.1 ). However, the methodologies used to estimate nonpoint source loads do not distinguish between NPDES stormwater discharges and non-NPDES stormwater discharges, and as such, this source assessment section does not make any distinction between the two types of stormwater.



### 4.2.1 Point Sources

Lake Lena Sub-basin

There are two active National Pollutant Disc harge Elimination System (NPDES) permitted facilities that are authorized to discharge to surface waters within the Lake Lena sub-basin: the City of Auburndale Allred Domestic Wastewater Treatment Facility (WWTF) (NPDES FL0021466) and the Florida Distillers Com pany – Auburndale (NPDES FL0003051). The Auburndale WWTF is a complete mix extended oxidation ditch domestic wastewater treatment facility, with a 1.4 million gallon a day (MGD) annual average daily flow. The facility is operated to achieve secondary treatment with basic disinfection for land application of effluent and/or advanced secondary treatment with basic disinfection and de-chlorination prior to discharging to Lake Lena Run, the outflow tributary from Lake Lena. Effluent disposal to Lake Lena Run is authorized up to a 0.65 MGD monthly average daily flow.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 35 The Florida Distillers facility is a citrus and cane molasses fermentation and bottling plant with a 2.6 MGD design capacity. The facility is involved in the manufacture of brandy, rum, and grain whiskey from cane, citrus, and grains. The materials are mashed with water, pasteurized, fermented, concentrated, and subsequently distilled, blended, and bottled. The liquid waste stream is evaporation condensate, cleaning water, cooling water, and sanitary wastewater. The wastewater undergoes neutralization, flow equalization and biological treatment through an activated sludge plant. The effluent is chlorinated, aerated and discharged through Outfall D002. Effluent disposal consists of a 0.5 MGD monthly average daily flow permitted surface water discharge to Lake Lena Run, the outflow tributary from Lake Lena.

The discharges from the Auburndale WWTP and Florida Distillers facility were considered significant enough, in terms of volumes and concentrations, to affect modeling results and as a result, were incorporated into the WAM model and in determining TMDL point source loads (see Figure 4.2 ).

Lake Parker Sub-basin

Two active permitted fossil fuel power generation facilities are located on the banks of Lake Parker: the Lakeland Larson Memorial Plant (NPDES FL0026298) and the Lakeland Electric McIntosh Plant (NPDES FL0026301). The Larsen facility has a design capacity of 115 MGD for unit #001 and 115 MGD for unit #002. The McIntosh facility has a design capacity of 115.2 MGD for unit #1, while Unit #2 ceased operations in 1988. The plants withdraw water from Lake Parker to use as once through cooling water and cooling tower make-up water and return the water to the lake. In essence, water is removed from the lake, used for cooling, and then returned to the lake with an insignificant volumetric loss or nutrient contribution. The Larsen and McIntosh facility discharges were not considered significant enough, in terms of volumes and concentrations, to affect modeling results and as a result, were not incorporated into the WAM model and in determining TMDL point source loads (see Figure 4.2 ).DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 36 Figure 4.2 Lake Hancock and Lower Saddle Creek Watershed Lake Control Structures and Active NPDES FacilitiesDRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 37 Municipal Separate Storm Sewer System Permittees
Municipal separate storm sewer systems (MS4s) may discharge nutrients to waterbodies in response to storm events. To address st ormwater discharges, the EPA developed the National Pollutant Discharge Elimination System (NPDES) stormwater permitting program in two phases. Phase I, promulgated in 1990, addresses large and medium MS4s located in incorporated places and counties with populations of 100,000 or more. Phase II permitting began in 2003. Regulated Phase II MS4s, which are defined in Section 62-624.800, F.A.C., typically cover urbanized areas serving jurisdictions with a population of at least 10,000 or discharges into Class I or Class II waters, or Outstanding Florida Waters.

The stormwater collection systems in the Lake Hancock Basin, which are owned and operated by Polk County in conjunction with the Florida Department of Transportation (FDOT), are covered by a NPDES Phase I MS4 permit ( Figure 4.3 ). The Lake Hancock and Lower Saddle Creek watersheds are situated between the cities of Lakeland, Winter Haven, Auburndale, and Bartow. The City of Lakeland has areas in it’s jurisdiction located within the Lake Hancock Basin. At this time, it is unknown if local governments located in the lake and creek watersheds have applied for coverage under the Phase II NPDES MS4 permit.

As a note, numerous Polk County stormwater Capital Improvement Projects (CIPs) are currently under construction or are anticipated in the near future that are designed to reduce nutrient and sediment loadings to lakes and watersheds that contribute water quantity and quality to Lake Hancock. Current and future projects address stormwater discharges from lakes Gibson, Hollingsworth, John, Mirror, Morton, and Parker.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 38 Figure 4.3 Phase I MS4 Coverage Areas for the Lake Hancock BasinDRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 39 4.2.2 Nonpoint Sources and Land Uses

Unlike traditional point source effluent loads, nonpoint source loads enter at so many locations and exhibit such large temporal variation that a direct monitoring approach is often infeasible. For the Lake Hancock and Lower Saddle Creek TMDLs, all nonpoint sources were evaluated by use of a watershed and lake modeling approach. Table 4.1 shows the existing area of the various land use categories examined and modeled for the Lake Hancock Basin. Figure 4.4 shows the drainage basin area for the lake and creek, and the spatial distribution of the existing land uses shown in Table 4.1. Figure 4.5 shows the spatial distribution of land use coverages for the Lake Hancock Basin when converted to “natural background” land cover.
The predominant existing land coverages for the Lake Hancock Basin (which includes all nine sub-basins) are low, medium, and high density residential (20.2%); followed by extractive-post phosphorus mining (16.2%); agriculture (14.2%); and commercial, industrial, transportation, and utilities (8.1%). These coverages account for 58.6 percent of the land use in the Lake Hancock Basin. Lakes and interconnected waterways/streams/wetlands etc. account for 23.2 percent of the watershed. The areas occupied by anthropogenic land uses account for 63.5 percent of the watershed.

Land use coverages for the Lake Hancock Basin were aggregated using the Florida Land Use, Cover and Forms Classification System (FLUCCS, 1999). The spatial distribution and acreage of different land use categories for WAM were identified using the 1999 land use coverage (scale 1:24,000) provided by the Southwest Florida Water Management District (SWFWMD) contained in the Lake Hancock Basin WAM model developed by Soil and Water Engineering Technology, Inc., (2005).DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 40 Table 4.1 Lake Hancock Basin Existing Land Use Descriptions

FLUCCS ID Lake Hancock Basin Existing Land Use Coverage Acres Sq Miles Percent 1600 Extractive-Phosphorus Mining 16,210.0 25.33 16.15% 1200 Medium Density Residential, Fixed Single Family Units 13,155.8 20.56 13.11% 5201 Interconnected Lakes 12,179.8 19.03 12.13% 2100 Pastures and Fields 8,942.7 13.97 8.91% 6150 Stream and Lake Swamps (Bottomland) 6,138.1 9.59 6.11% 1800 Recreation 4,989.0 7.80 4.97% 2210 Citrus Groves 4,875.4 7.62 4.86% 1100 Low Density Residential, Fixed Si ngle Family Units 4,304.6 6.73 4.29% 1400 Commercial and Servic es 3,679.4 5.75 3.67% 4340 Hardwood - Conifer Mixed 2,908.4 4.54 2.90% 1300 High Density Residential, Fixed Si ngle Family Units 2,834.3 4.43 2.82% 5300 Reservoirs 2,619.3 4.09 2.61% 1900 Undeveloped Land 2,043.6 3.19 2.04% 1500 Industrial 1,991.7 3.11 1.98% 6410 Freshwater Marshes 1,692.7 2.64 1.69% 8100 Transportation 1,556.8 2.43 1.55% 6210 Cypress 1,349.2 2.11 1.34% 2600 Old Field 1,346.7 2.10 1.34% 1700 Educational Facilit ies 1,238.0 1.93 1.23% 4110 Pine Flatwoods 1,215.8 1.90 1.21% 8300 Utilities 859.9 1.34 0.86% 7400 Barren Land 761.1 1.19 0.76% 3200 Prairies 600.5 0.94 0.60% 6300 Wetland Forested Mixed 575.8 0.90 0.57% 4200 Upland Hardwood Forest 437.4 0.68 0.44% 6440 Emergent Aquatic V egetation 378.1 0.59 0.38% 5200 Lakes 355.8 0.56 0.35% 6430 Wet Prairies 274.3 0.43 0.27% 2410 Tree Nurseries 165.6 0.26 0.16% 3100 Herbaceous 135.9 0.21 0.14% 2140 Row Crops 126.0 0.20 0.13% 6200 Wetland Coniferous Forest 98.8 0.15 0.10% 4100 Upland Coniferous Forests 93.9 0.15 0.09% 3290 Other Shrubs and Brush 66.7 0.10 0.07% 2520 Dairies 61.8 0.10 0.06% 2550 Tropical Fish Farms 29.7 0.05 0.03% 6530 Inland Shores/Ephemeral Ponds 29.7 0.05 0.03% 8200 Communications 22.2 0.03 0.02% 2310 Cattle Feeding Operation 19.8 0.03 0.02% 6100 Mixed Wetland Hardwoods 12.4 0.02 0.01% 4400 Coniferous Plantations 7.4 0.01 0.01% Total 100,383.5 156.85 100DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 41 Figure 4.4 Lake Hancock and Saddle Creek Existing Land Use CoverageDRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 42 Figure 4.5 Lake Hancock and Saddle Creek Natural Background Land Use CoverageDRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 43 Polk County Population
According to the U.S Census Bureau, the population density in Polk County, in the year 2000, was at or less than 258.2 people per square mile. The Census Bureau reports that the total population in 2000 for Polk County, which includes (but is not exclusive to) the Lake Hancock and Lower Saddle Creek watersheds, was 483,924, with 226,376 housing units. Polk County occupies an area of approximately 2,009 square miles. For all of Polk County, the Census Bureau reported a housing density of 120.8 houses per square mile. Polk County is just below the average housing density for Florida counties of 134.3 housing units per square mile (U.S. Census Bureau Web site, 2004).

Polk County Septic Tanks

Onsite sewage treatment and disposal system s (OSTDSs), including septic tanks, are commonly used where providing central sewer is not cost-effective or practical. When properly sited, designed, constructed, maintained, and operated, OSTDSs are a safe means of disposing of domestic waste. The effluent from a well-functioning OSTDS is comparable to secondarily treated wastewater from a sewage treatment plant. When not functioning properly, however, OSTDSs can be a source of nutrients (nitrogen and phosphorus), pathogens, and other pollutants to both ground water and surface water.
As of 2001, Polk County had a cumulative registry of 112,848 septic systems. Data for septic tanks are based on 1970 – 2001 census results, with year-by-year additions based on new septic tank construction. The data do not reflect septic tanks that have been removed going back to 1970. From fiscal years 1993–2004, 1,151 permits for repairs were issued in Polk County (Florida Department of Health, 2004). Based on the number of permitted septic tanks and housing units (226, 376) located in the county, approximately 50 percent of the housing units are connected to a central sewer line (i.e., wastewater treatment facility), with the remaining 50 percent utilizing septic tank systems

. 

### 4.3 Estimating Poin t and Nonpoint Source Loadings

Model Approach

WAM was utilized to estimate the nutrient loads within and discharged from the Lake Hancock Basin. WAM is a Geographic Information System (GIS) based model that allows users to interactively simulate and assess the environmental effects of various land use changes and associated land use practices.

WAM utilizes ESRI TM 

### ArcView 3.2 with Spatial Analyst 2.0 to analyze and display model input and output using grids. Grid datasets, as opposed to polygon datasets, spatially represent geographic data as a collection of raster cells. Each cell contains attributes of the dataset, (e.g., land use code numbers) that can be overlaid with cells of other grids. The benefits of using grids over polygons include computational speed and output resolution. Output can be displayed by grid cell, as opposed to by sub- basin polygon. The cell size is dependant on the desired resolution. A grid cell size of one hectare was chosen, with the intent that this would adequately characterize the land use and capture linear features such as highways (SWET, 2005).DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 44 The WAM model water quality parameters (impact parameters) simulated for Lake Hancock and the Saddle Creek watershed included: Water quantity, soluble nitrogen (N) forms (ammonia, soluble organic, nitrate), particulate N, ground water N, soluble phosphorus (P), particulate P, ground water P, sediment, 5-day biochemical oxygen demand (BOD 5 

### ), and land sourced dissolved oxygen. GIS datasets of land use, soils and rainfall are used to calculate the combined impact of the watershed characteri stics for a given grid cell. Once the combined impact for each unique cell within a watershed is determined, the cumulative impact for the entire watershed is determined by attenuating the constituent to the sub-basin outlets. Constituents are attenuated based upon the flow distances (overland to nearest water body, through wetlands or depressions and within streams to the sub-basin outlet), flow rates in each related flow path and the type of wetland or depression encountered. Figure 4.6 shows the conceptual routing schemes and flow distances that are calculated for each cell (SWET, 2005).

Figure 4.6 WAM Conceptual Routing Diagram (SWET, 2005)


### A portion of the flow in each cell is converted to ground water based on the soil type and the amount of imperviousness estimated for each land use. Surface flow that enters depressions is also converted to ground water. Ground water is routed to the nearest stream unless directed otherwise.

The hydrologic contaminant transport modeling is accomplished by first simulating all of the unique grid cell combinations of land use, soils, and rainfall by using one of several source cell models including GLEAMS (Knisel, 1993), EAAMOD (Bottcher et al., 1998; SWET, 1999), a wetland module, and an urban module. The time series outputs for each grid cell is then routed and attenuated to the nearest stream and then through the entire stream network of the watershed. Dynamic routing of flows is accomplished through the use of an algorithm, BLASROUTE.exe, that uses a non-linear reservoir technique (Jacobson et al., 1998). Figure 4.7 shows a flow diagram of the hydrologic co ntaminant transport modeling component of the overall WAM model. Depression

Overland

Wetland Stream

Flow Routing Grid Cell

Basin Outlet GW Wetland

(1 ha)DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 45 Field Model Parameters Files

Unique LU/Soil

Grid Cell Coverages Cell Loads Cumulative Loads WAM INTERFACE (Algorithms & SubModels Executed)

WAM Outputs and Intermediate files Data Inputs Databases

GIS Coverages Attenuation Coefficients Distance Covera g e Land Use Topography

Unique Parameter

Sets Land Attenuation PreProcessing

Stream Reach Flow Rates & Concentrations GIS Covera g e

A SCII Datefile

Interface O p eration

Stream Routing Network River Outlet Stages Hydrography Subbasins

Land Use

(LU) Soils

Rainfall Zone ( new ) Land Use Soils Default Values

BUCSHELL BLASROUTE
Create/Link Model

Parameter Sets for Cells Simulate Unique Cells for Load

Estimates Overlay Coverages Attenuate to Streams Stream Routing Fortran SubModel LEGEND

Edit Land Use

& Display I/O Files Generate Attenuation Distances

Climatic Data Sewage Serv. Area



### Figure 4.7 WAM Dynamic Modeling Approach (SWET, 2005)


### While BATHTUB has the capability to simulate large, sinuous reservoirs and lakes using multiple model cells, the size and nature of the eleven lakes evaluated supported the designation of one BATHTUB segment for each lake. However, because of the interconnectedness of the eleven lakes, including Lake Hancock, all eleven lakes were incorporated into a single BATHTUB model framework containing eleven linked segments. The outflow from each lake enters the next lake downstream. Surface water and ground water inputs are designated as tributaries in the model (one set to each lake). These inputs are provided by WAM which was explicitly set up to output the incremental surface water and ground water quantity and quality flowing into each of the BATHTUB-simulated lakes. That is, the tributaries designated in the BATHTUB model have flows and concentrations that reflect their local upstream (between lakes) source s only. Ground water seepage from each lake is simulated using BATHTUB’s channels. A schematic of the model framework is shown in Figure 4.8. All flows that do not point to a lake represent flows that are lost to the system. Daily WAM results were computed for the time period 1994 to 2003. The WAM results were averaged on an annual basis to develop eleven separate BATHTUB model scenarios, one for each year (QEA, LLC, 2005).DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 46 Figure 4.8 Model Schematic Depicting the Interconnected Eleven Lakes Modeled for the Lake Hancock Watershed (QEA, 2005)

Land Use and Soils
All of the GIS spatial datasets necessary to set up WAM were provided by the Department in custom Albers projection in the HPGN (metric) datum. Most of the datasets are from other sources including Southwest Florida Water Management District (land use), Natural Resource Conservation Service (soils), and United States Geographical Survey (topography and hydrography). The SURGO soils datasets were modified to include abbreviated soil designations so that these attributes would match WAM soils database established for the State. The land use dataset utilizes the Florida Land Use Cover Classification System (FLUCCS), which is also utilized by WAM (as noted in Chapter 4, Section 4.2.2 ).

Hydrologic Data
National Hydrologic Datasets (NHDs) were reviewed but were not used because of the lack of information and ability to define the hydrologic stream network within the Lake Hancock Basin. Instead, a detailed water management modeling assessment performed by Keith and Schnars, P. A., (2003) for the Polk County Board of County Commissioners and SWFWMD was utilized. Banana SW

GW GW Lena SW

GW GW

Hancock SW

GW

Out of Model Domain Bentley SW

GW GW Hollings

-

worth SW

GW GW

Eagle SW

GW GW Spirit SW

GW GW Gibson SW

GW GW

Crago SW

GW GW

Parker SW

GW GW

Bonny SW

GW GW

SW=Surface Water GW=Ground WaterDRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 47 The Primary Basin Setup procedure available in WAM was utilized to layout and code the stream network. The line segments of the Keith and Schnars reach coverage were coded with numbers in descending order from upstream to downstream. Not all of the segments were utilized. For modeling purposes, it is possible to represent clusters of segments as one reach. Line segments were added along the boundaries of the lakes to form shorelines. These shorelines were needed to properly calculate overland distances to the lakes (used for attenuation). In total, 98 hydrologic model reaches were assigned. A profile of these reaches is shown in Figure 4.9 (SWET, 2005).

Figure 4.9 Model Reaches and Estimated Depressions Attenuation Distances

Depressions
Depressions are one of the three geographic features (wetlands, streams and depressions) that WAM routes runoff to and attenuates. Areas that drain to depressions are attenuated differently than areas that drain via surface water to the streams. Runoff entering depressions converts to ground water with very little phosphorus re-emerging in the streams. A grid of topographical and potential isolated depressional areas were created by an algorithm in the WAM Primary Basin Setup. This algorithm utilizes wetlands from the land use dataset, depressional soils such as surrency of the so ils dataset, hydrography and topography. A gridDRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 48 of topographical depressed areas is produced based on the topography grid, which was created from the USGS DEMs. Grid functions available in ArcView TM 

### Spatial Analyst were then used to locate depressions and determine their minimum elevation and depth at which runoff overflow would occur. The depth is added to the minimum elevation to determine the overflow elevation. All elevations equal to or less than this elevation in the region of the sink are identified and converted to a new grid of topographic depressions. A wetland and depressional soil grid was then created by selecting and merging those features from their respective source grids. These areas represent potentially depressional areas as opposed to topographic depressions. Both grids are then converted to polygon shapefiles. Potential depressions that lie in areas where land slopes are sufficient to generate runoff discharge are removed. The topography grid is then used to create a grid of slope values. Polygons of potential depressional areas that lie over an area with an average slope that is above a set minimum slope are then removed.

The hydrography dataset is used in the algorithm to eliminate areas that are on or near “connected” hydrologic features. Connected feat ures represent those line segments of the hydrography that form a contiguous drainage network including boundaries of lakes and wetlands. Any such boundaries that are isolated away from the connected system are not utilized in the analysis. Polygons that are within a set distance from the connected system are removed in both the topographic and potential depression shapefiles. This is based on the assumption that if the depression is close enough to the stream network, it is most likely connected to the network.

A new screening process, however, was added spec ifically for the Lake Hancock watershed study when it was discovered that several small topographic depressions were appearing in heavily urbanized areas. Considering the nature of urban drainage, it is likely that drainage from these areas is captured and conveyed by lo cal culverts. The algorithm was modified to exclude depressions in areas dominated with urban land use. Figure 4.9 shows the results of the analysis for depressions and stream reaches (SWET, 2005).

WAM attenuates water quality parameters in the runoff based on distances and the type of geographic feature the runoff passes through (upland, wetland, depression and stream). The WAM Primary Basin Setup includes an algorithm to develop a series of grids for this purpose. ArcView TM 

### Spatial Analyst cost distance functions are used to both determine distance and attributes of the feature that is found. For example, when the closest wetland is found, the wetland FLUCCS number can also be returned. In addition, a grid of wetland distances to streams can be accessed to return the distance to the next feature (SWET, 2005).DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 49 Rainfall

Rainfall datasets were created from monitoring information obtained from the National Weather Service (NWS). The stations were initially chosen based on their locations for adequate spatial coverage of the study area and for the appropriate period of record. For flexibility in modeling, it is important to have an adequate period of record. A 13-year period between January 1992 and December 2004 was chosen, though it was expected that the model would not utilize this entire period. The model uses the first two years of data to reach equilibrium with antecedent conditions. The model output reflects any remaining years of input data. Only years 1994 to 2003 were used for generating files for the BATHTUB model.

The rainfall records were then reviewed for completeness. Some stations were rejected because of abnormal annual rainfall compared to surrounding stations. The three USGS stations shown were first considered, but upon data review the Winter Haven station appeared to be quite different from the other two stations. When it was found that this station’s data had not been verified after 1999, it was decided to use only the Bartow (COOP: 080478) and Lakeland (COOP: 084797 and COOP: 084802) National Weather Service stations. These data were retrieved from the Climate Interactive Rapid Retrieval User System (CIRRUS) host ed by the Southeast Regional Climate Center, 2005. The data from the selected rainfall stations was formatted and converted to centimeters for use by WAM. Theissen’s polygon method was applied to create rainfall zones for the stations noted above and shown in Figure 4.10

.
Control Structures

Six major water control structures located within the Lake Hancock and Saddle Creek watershed were incorporated into the WAM model. These structures are located at lakes Arietta (P-3), Banana, Gibson, Hancock/Lower Saddle Creek (P-11), Lena (P-1), and Parker. Most of the structures in this basin consist of weirs that are operated to maintain optimum lake elevations. The major control structures ( Figure 4.2 ) are operated and maintained by the Southwest Florida Water Management District. Several other smaller structures were added to the model to simulate culvert connections and other water control features. The elevation controls were adjusted to reflect observed water levels throughout the basin (SWET, 2005).

Ground Water

An option in WAM allows ground water to be routed to specified locations as opposed to the closest downstream waterbody, which is how surface water is routed. This option is particularly useful for dealing with springsheds or with deep surficial systems where ground water emerges further downstream as opposed to the nearest stream. It is also possible to send ground water out of the system to an offsite spring or as recharge to underlying aquifer Fi g ure 4.10 Rainfall Stations and ZonesDRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 50 system by designating the ground water zone as discharging to reach number 1, which by default is an offsite reach. In the Lake Hancock Basin, it was assumed that some ground water discharges to nearby streams/lakes, while the majority percolates to the deeper Upper Floridian Aquifer (UFA). To reflect this, buffers were created around the streams and lakes (200 meters for streams and 500 meters for lakes) that included ground water zones equal to the nearest reach number. Reach number 1 was assigned to any areas outside of these buffers. Figure 4.11 shows the zones of surface water (Stream Node) and ground water (GW Node) distribution. Areas shaded in gray discharge to the UFA (SWET, 2005).

Stream Node GW Node


### Figure 4.11 Surface Water and Ground Water Distribution Zones
Several previous studies in the Lake Hancock Basin found that significant leakage to the UFA is occurring from most of its lakes and str eams. For example, Environmental Research and Design (1999) estimated by in-situ leakage studies and USGS data that Lake Hancock receives about 4-6 inches of ground water inflow per year, but leaks between 25 to 35 inches to the UFA per year. To better handle this leakage component in the basin, WAM was modified so that leakage rates for each stream and lake reach could be assigned. These leakage rates are the primary calibration factors for this basin. This leakage rate is calculated by the following equation:
Reach leakage rate (m 3 

### /y) = Area x K leak 

### x Relative Head

Where, Area = reach’s water surface area (m 2 

### ) K leak 

### = leakage coefficient (m/y) Relative Head = (water surface elevation – impeding layer elevation)/ unit thickness – dimensionless (SWET, 2005)DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 51 WAM Model Linkage to the BATHTUB Model
GIS and model data set inputs for the WAM model included land use, soils, topography and depressions, hydrogaphy, USGS gage and flow vo lume, septic tanks, water use pumpage, point sources, rainfall, ground water, atmospheric deposition, solar radiation, control structures, and attenuation distances/stream reaches.

The BATHTUB model simulates lake water quality based on annual average inputs. The inputs required for BATHTUB are the following annual data: rain (amount and TN and TP concentrations), evaporation, surface water inflow volumes and TN and TP loads, ground water inflow volumes and TN and TP loads, and leakage volume. Because BATHTUB is unable to vary the rainfall rate between lakes, it was decided that WAM would include rain inputs as part of its surface reach loads, so that the rain zones could be represented. Therefore, BATHTUB inputs show no rainfall. BATHTUB has been set up to simulate Lake Hancock and its ten major contributing lakes. The flow routing to and between lakes is built into both WAM and BATHTUB. BATHTUB routes flow and constituents between lakes, but requires WAM to provide all flow and constituents generated above and between the lakes.

Using the BATHTUB input decks, WAM produced a nonpoint source file for each lake reach that contained all of the inflow and constituent loads data needed by BATHTUB. These files and the normal WAM reach files were used by an Access database which processed and formatted the input data necessary for BATHTUB (SWET, 2005).

WAM and BATHTUB Calibration

The data used for calibration is included in the Department’s IWR database and the Polk County Water Atlas database. The WAM model was initially set up based on parameters presented in the modeling report just completed by BCI Engineers & Scientists, Inc. (2005). This report was extremely helpful, however, upon data review and discussion with local experts it was found that some of the structures, particularly their control elevations, had to be updated. Also, in the western basin near Lake John, the hydrography was verified to be quite different than what was shown in the report (i.e., Lake John was found to flow north and east through Summerset Lake instead of south). Also, a major culvert into the southeast end of Lake Crago from a series of old mining pits was also not represented. All of the flow and structure setting were verified against available lake stage data, which deemed the best hydrology data available to calibrate against because it was available throughout the basin. There were three flow stations located with the basin that were also used to verify net flow volumes.

The parameters varied to obtain the best fit were the weir crest elevations for the lake structures and the leakage rates for each reach. The nearly closed lakes, such as Eagle, Spirit, Thomas, and Arietta, were the most difficult to calibrate because getting the leakage rates correct required numerous trial and error runs. Also, the balance of leakage between connected lakes like Parker, Crago, and Bonny required special attention so that significant backflow between the lakes was not generated, though some backflow is probably real.
Another calibration issue was the 3-foot culvert from the upper end of Lake Crago to the connected mine pits located to the northeast. The reasonable leakage rates in these pits created the situation that there was a net positive flow from Lake Crago to these pits. WAM was able to handle this net negative reach inflow, but BATHTUB was not. Therefore, since the flows through this culvert were quite low compared to the other inflow to the lake, theDRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 52 culvert was raised to prevent flow except during major events. This solved the BATHTUB problem and did not have a significant impact on the assimilative capacity for Lake Hancock.

Water quality calibration was limited by the fact that only in-lake data were available and WAM currently does not have a lake sub-model to properly represent the nutrient dynamics, particularly internal loadings from bottom sediments, algal populations, and macrophytes. These limitations were the reason WAM was linked to BATHTUB, which is capable of handling the in-lake dynamics much better and on a long term basis. WAM performed fairly well in matching the general nutrient levels in several of the lakes, which gives confidence that the simulated nutrient loading rates to the lakes are reasonable (SWET, 2005).

Lake Hancock Basin Existing Land Use Loadings

The total loadings of nitrogen and phosphorus generated in the Lake Hancock Basin were estimated using the WAM and BATHTUB models. Modeling frameworks were designed to simulate the period 1994 through 2003. This time period had the best available seasonal data for the contributing sub-basins and also included the verified period for Group 3 waterbodies located in the Lake Hancock watershed.

Based on the hydrology, and lake and stream interconnected reaches, nine major sub-basins were delineated in making up the Lake Hancock watershed. The nine sub-basins include Banana Lake and Banana Lake Canal, Cabbage Branch, Eagle Lake, K-Ville Branch, Lake Lena and Lake Lena Run/Creek, Lake Parker, Lower Saddle Creek, Middle Saddle Creek, and Upper Saddle Creek. Within the nine sub-basins making up the Lake Hancock watershed, eleven lakes were targeted and modeled based on nutrient impairment and the interconnected nature of the waterbodies contributing runoff and loadings to Lake Hancock and Lower Saddle Creek. The eleven lakes are Lake Gibson, Lake Crago, Lake Bonny, Lake Parker, Lake Lena, Lake Hollingsworth, Lake Bentley, Banana Lake, Spirit Lake, Eagle Lake, and Lake Hancock. All of these lakes are impaired for nutrients based on the Department’s Impaired Waters Rule methodology. Each lake was modeled separately to determine individual contributions to Lake Hancock and Lower Saddle Creek. Tables 4.2 through 4.7 illustrate the total water volume and loadings for TN and TP going into each of the eleven lakes from 1994 to 2003 based on the WAM and BATHTUB model results under current land use conditions. Loads were estimated based on lake surface rainfall, surface water inflow, ground water inflow, and septic inflow. Ground water loss/leakage from each lake was also calculated and subtracted from the total inflow volume.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 53 Table 4.2 Lakes Gibson and Crago Water Volume and Loadings for TN and TP from 1994 to 2003

Lake Gibson Lake Crago

Year Water (hm 3 ) TN (kg) TN (lbs) TP (kg) TP (lbs) Water (hm 3 ) TN (kg) TN (lbs) TP (kg) TP (lbs) 1994 6.7 10,815.4 23,843.9 836.9 1,845. 1 1.8 1,532.0 3,377.6 206.5 455.2 1995 7.0 13,422.2 29,590.9 864.3 1,905. 5 1.3 975.5 2,150.7 124.9 275.4 1996 5.5 8,323.0 18,349.1 714.1 1,574. 4 1.4 1,050.1 2,315.0 173.4 382.3 1997 8.4 16,079.5 35,449.3 1,182.1 2,606. 2 1.4 1,249.8 2,755.3 153.9 339.2 1998 6.9 12,176.4 26,844.4 870.4 1,918. 8 1.3 986.6 2,175.0 122.8 270.7 1999 4.7 8,676.8 19,129.0 642.2 1,415. 8 1.2 1,117.2 2,463.1 156.0 343.8 2000 3.7 8,950.2 19,731.8 516.1 1,137. 9 0.9 1,025.8 2,261.4 118.7 261.8 2001 4.7 10,787.6 23,782.6 710.6 1,566. 6 0.9 806.1 1,777.1 96.4 212.5 2002 8.3 12,066.5 26,602.1 1,061.1 2,339. 3 1.8 1,479.6 3,262.1 197.8 436.0 2003 6.9 13,944.7 30,742.9 829.8 1,829. 4 1.0 713.7 1,573.3 78.7 173.4
94-03 Mean 6.3 11,524.2 25,406.6 822.8 1,813. 9 1.3 1,093.6 2,411.1 142.9 315.0 94-03 Totals 62.7 115,242.4 254,066.1 8,227.7 18,138.9 12.9 10,936.4 24, 110.6 1,429.0 3,150.3
hm 3 : Cubic Hectometers; kg: Kilograms; lbs: Pound



### Table 4.3 Lakes Bonny and Parker Water Volume and Loadings for TN and TP from 1994 to 2003

Lake Bonny Lake Parker

Year Water (hm 3 ) TN (kg) TN (lbs) TP (kg) TP (lbs) Water (hm 3 ) TN (kg) TN (lbs) TP (kg) TP (lbs) 1994 3.9 3,832.2 8,448.6 448.5 988.8 28. 5 23,624.2 52,082.4 3,330.8 7,343.2 1995 4.1 5,263.8 11,604.8 472.2 1,041.0 29.6 30,685.8 67,650. 7 3,408.7 7,514.9 1996 3.0 2,429.4 5,356.0 359.1 791.6 22. 5 16,120.8 35,540.4 2,649.8 5,841.8 1997 4.9 6,951.3 15,324.9 629.3 1,387.4 35.3 39,650.4 87,414. 2 4,436.6 9,780.9 1998 4.0 4,340.0 9,568.0 467.7 1,031.0 28.4 27,585.3 60,815. 1 3,253.2 7,172.2 1999 2.6 2,514.3 5,543.0 308.2 679.5 19. 5 16,428.3 36,218.1 2,343.8 5,167.3 2000 2.0 2,468.3 5,441.7 238.0 524.8 15. 0 15,148.7 33,397.1 1,790.9 3,948.2 2001 2.6 3,400.4 7,496.6 333.5 735.1 19. 7 22,304.7 49,173.5 2,485.4 5,479.4 2002 4.8 4,674.1 10,304.6 579.2 1,276.9 34.8 29,299.0 64,593. 3 4,136.2 9,118.8 2003 4.1 5,095.4 11,233.4 447.8 987.1 28. 6 32,376.8 71,378.6 3,201.5 7,058.0
94-03 Mean 3.6 4,096.9 9,032.2 428.3 944.3 26. 2 25,322.4 55,826.3 3,103.7 6,842.5 94-03 Totals 36.0 40,969.3 90,321.8 4,283.4 9,443. 2 261.8 253,224.0 558,26 3.4 31,036.9 68,424.6
hm 3 : Cubic Hectometers; kg: Kilograms; lbs: PoundsDRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 54 Table 4.4 Lakes Lena and Banana Water Volume and Loadings for TN and TP from 1994 to 2003

Lake Lena Banana Lake

Year Water (hm 3 ) TN (kg) TN (lbs) TP (kg) TP (lbs) Water (hm 3 ) TN (kg) TN (lbs) TP (kg) TP (lbs) 1994 3.1 4,862.6 10,720.3 380.5 838.8 11. 8 19,178.6 42,281.6 1,846.3 4,070.4 1995 4.7 9,690.2 21,363.2 637.0 1,404.4 13.1 21,642.2 47,713. 0 2,048.2 4,515.4 1996 1.9 1,550.2 3,417.7 229.3 505.4 9. 0 13,498.4 29,759.0 1,459.6 3,217.9 1997 4.6 10,021.9 22,094.6 732.4 1,614.6 16.8 29,160.4 64,287. 7 3,015.3 6,647.7 1998 5.6 9,849.3 21,714.1 794.6 1,751.8 14.4 17,896.8 39,455. 8 2,342.6 5,164.6 1999 1.4 1,861.0 4,102.8 163.6 360.7 7. 5 12,011.8 26,481.5 1,261.5 2,781.2 2000 1.1 2,326.6 5,129.2 126.9 279.8 5. 8 12,030.6 26,522.8 1,003.4 2,212.1 2001 1.4 2,823.9 6,225.6 204.5 450.9 8. 4 16,435.4 36,234.0 1,553.9 3,425.7 2002 2.8 3,903.2 8,605.1 374.8 826.3 15. 5 25,754.7 56,779.4 2,566.8 5,658.7 2003 6.1 11,516.0 25,388.3 887.8 1,957.3 14.5 19,000.5 41,889. 0 2,247.6 4,955.2
94-03 Mean 3.3 5,840.5 12,876.1 453.1 999.0 11.7 18,661.0 41,140. 4 1,934.5 4,264.9 94-03 Totals 32.7 58,404.9 128,760.8 4,531. 4 9,990.0 116.8 186,609.6 411,403.7 19,345.2 42,649.0
hm 3 : Cubic Hectometers; kg: Kilograms; lbs: Pounds



### Table 4.5 Lakes Hancock and Hollingsworth Water Volume and Loadings for TN and TP from 1994 to 2003

Lake Hancock Lake Hollingsworth

Year Water (hm 3 ) TN (kg) TN (lbs) TP (kg) TP (lbs) Water (hm 3 ) TN (kg) TN (lbs) TP (kg) TP (lbs) 1994 84.3 95,809.9 211,224.8 12,901.6 28,443. 2 4.9 12,135.9 26,755.1 560.5 1,235.6 1995 92.7 104,720.5 230,869.2 15,015.7 33, 104.0 5.2 16,619.0 36, 638.7 578.3 1,274.9 1996 67.0 70,727.9 155,928.3 11,013.8 24, 281.4 3.9 3,107.1 6,850.0 438.6 966.9 1997 127.8 134,996.1 297,615.5 23,884.2 52, 655.7 6.3 21,147.9 46, 623.1 703.9 1,551.9 1998 108.4 109,122.0 240,572.9 19,501.5 42, 993.5 5.2 14,557.2 32, 093.2 525.4 1,158.4 1999 56.5 62,991.0 138,871.5 9,798.8 21, 602.7 3.4 8,036.1 17,716.6 387.7 854.7 2000 45.9 59,478.1 131,126.9 8,443.0 18, 613.5 2.6 9,500.9 20,946.0 290.4 640.2 2001 66.7 78,445.6 172,943.0 12,962.3 28, 576.9 3.4 11,431.4 25,201.9 393.6 867.7 2002 115.5 116,668.0 257,208.9 19,492.5 42, 973.6 6.1 13,817.9 30, 463.3 685.9 1,512.2 2003 106.6 109,343.0 241,060.2 18,321.6 40, 392.2 5.2 15,868.4 34, 983.8 532.0 1,172.9
94-03 Mean 87.1 94,230.2 207,742.1 15,133.5 33, 363.7 4.6 12,622.2 27, 827.2 509.6 1,123.5 94-03 Totals 871.4 942,302.2 2,077,421.2 151, 335.0 333,636.7 46.3 126,221. 9 278,271.6 5,096.3 11,235.4
hm 3 : Cubic Hectometers; kg: Kilograms; lbs: PoundsDRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 55 Table 4.6 Lakes Bentley and Spirit Water Volume and Loadings for TN and TP from 1994 to 2003

Lake Bentley Spirit Lake

Year Water (hm 3 ) TN (kg) TN (lbs) TP (kg) TP (lbs) Water (hm 3 ) TN (kg) TN (lbs) TP (kg) TP (lbs) 1994 1.3 4,284.4 9,445.5 152.1 335.3 1.5 4,763.4 10,501.5 159.7 352.1 1995 1.4 6,427.2 14,169.5 161.9 356.8 1.7 5,624.3 12,399.5 190.6 420.1 1996 1.0 766.5 1,689.9 122.6 270.4 1.5 3,569.4 7,869.2 151.5 334.0 1997 1.7 8,138.6 17,942.5 213.8 471.4 2.0 7,601.4 16,758.3 261.3 576.1 1998 1.5 5,158.4 11,372.2 159.9 352.6 1.8 5,268.1 11,614.1 240.6 530.3 1999 0.9 2,538.9 5,597.4 110.5 243.6 1.5 3,384.1 7,460.7 144.0 317.5 2000 0.7 3,372.4 7,434.9 85.7 188.9 1.4 3,087.4 6,806.6 120.6 265.9 2001 0.9 4,548.1 10,026.9 119.4 263.3 1.4 4,070.3 8,973.6 127.7 281.5 2002 1.6 4,396.0 9,691.4 191.7 422.7 2.0 7,608.7 16,774.2 265.3 585.0 2003 1.5 6,054.5 13,347.9 156.2 344.3 1.8 5,790.5 12,765.9 232.0 511.6
94-03 Mean 1.3 4,568.5 10,071.8 147.4 324.9 1.7 5,076.8 11,192.4 189.3 417.4 94-03 Totals 12.6 45,685.0 100,718.1 1,473.8 3, 249.2 16.5 50,767.7 111,92 3.6 1,893.3 4,174.0
hm 3 : Cubic Hectometers; kg: Kilograms; lbs: Pounds



### Table 4.7 Eagle Lake Water Volume and Loadings for TN and TP from 1994 to 2003

Eagle Lake

Year Water (hm 3 ) TN (kg) TN (lbs) TP (kg) TP (lbs) 1994 5.7 21,801.6 48,064.3 624.6 1,377.1 1995 5.9 22,129.8 48,788.0 647.2 1,426.9 1996 4.6 15,462.0 34,087.9 560.3 1,235.2 1997 7.2 28,597.2 63,046.1 811.8 1,789.6 1998 5.9 19,421.4 42,816.8 649.4 1,431.8 1999 4.0 15,395.9 33,942.2 510.2 1,124.8 2000 3.5 17,420.4 38,405.5 489.6 1,079.5 2001 4.1 21,855.3 48,182.8 543.6 1,198.4 2002 7.1 25,974.2 57,263.3 753.4 1,661.0 2003 5.8 19,534.5 43,066.1 613.5 1,352.6 94-03 Mean 5.4 20,759.2 45,766.3 620.4 1,367.7 94-03 Totals 53.7 207,592. 3 457,662.9 6,203.7 13,676.9
hm 3 : Cubic Hectometers; kg: Kilograms; lbs: PoundsDRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 56 

# Chapter 5: DETERMINATION OF ASSIMILATIVE CAPACITY

5.1 Determination of Loadi ng Capacity for TN and TP

Nutrient enrichment and the resulting problems related to eutrophication tend to be widespread and are frequently manifested far (in both time and space) from their source. Addressing eutrophication involves relating water quality and biological effects (such as photosynthesis, decomposition, and nutrient re cycling), as acted upon by hydrodynamic factors (including flow, wind, tide, and salinity) to the timing and magnitude of constituent loads supplied from various categories of pollution sources. The assimilative capacity should be related to some specific hydro-meteorological condition such as an ‘average’ during a selected time span or to cover some range of expected variation in these conditions. Lake Hancock was modeled as part of an eleven lake se ries over a ten-year period of record (1994 – 2003).

As discussed in Chapter 4, the WAM model was selected as the watershed model. It was run dynamically through the ten-year period of record with all the lakes linked together in their current configuration. BATHTUB was selected as the lake model. It was set up with all the lakes linked together and the model calibrated based on the annual average output from WAM and run year-by-year (1994 – 2003) for all eleven lakes.



### 5.1.1 Rainfall

The long-term average for the two rainfall gages used in the model [Bartow (COOP: 080478) and Lakeland (COOP: 084797 and COOP: 084802) National Weather Service stations] was 52.01 inches/year. The 10-year average rainfall for the study period (1994 – 2003) was 55.23 inches for Lakeland (60 th 

### percentile of the Lakeland long-term record) and 55.19 inches for Bartow (71st percentile of the Bartow long-term record) (see Table 5.1 ). Therefore, the study period represented a wetter than average period. However, it contained a very dry year, the year 2000, that was the driest year with 38.3 inches of rain recorded in Lakeland (10 th 

### percentile of the long-term record) and with 35.9 inches recorded at Bartow (~ the 1st percentile of the long-term record). For the year 2000, evaporation exceeded rainfall. This created a year with very high in-lake concentrations in both the current condition and natural land use background scenario.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 57 Table 5.1 Bartow and Lakeland, Florida, Rainfall Stations Used for Model Loading and Calibration

Note: Lakeland stations missing dat a from September and October 1995.



### 5.1.2 Model Calibration

Watershed Assessment Model (WAM)
WAM was calibrated by consultants for conditions in the years 1994 – 2003. Calibration consisted of a water balance approach to match the measured in-lake stages and flows at flow measuring points. An Access database tool was created to aggregate the daily predictions for surface water and ground water (flows and TN, TP concentrations) up to annual average conditions in a format compatible with the requirements of the BATHTUB model. For details on the WAM model see “WAM Watershed Assessment Model, Model Documentation and Users Manual,” Soil and Water Engineering Technology, Inc., 2005 ( Appendix J ). For details on model calibration see the WAM Final Report, September, 2005 ( Appendix H ).

BATHTUB Model

The consultant provided the Department with copies of ten BATHTUB input decks (one for each year 1994 – 2003) set up for current conditions, but not calibrated. The Department calibrated the BATHTUB model, which consisted of running each model year through all of the model options in BATHTUB to determine which set of models provided the best un-calibrated fit to the measured data. As a result of running through these models, it became apparent that for many of the lake/year combinations the watershed model was not delivering enough mass to match the measured data for either TN or TP. However, in other lake/year combinations, there was too much mass. Once a set of models was selected, the primary calibration for TN and TP was achieved by invoking BATHTUB’s internal loading rate functions for both TN and TP to match the measured in-lake mass. This Internal Loading (IL) rate integrates all of the missing mass. It is not proposed that the IL rate represents only those in-lake processes that either recycle mass within the lake or fix nitrogen from the atmosphere; it also includes all other missing mass. As such, it will be referred to as the Rainfall from Bartow and Lakeland Bartow 1900-2004 average = 53.7” Lakeland 1949-2004 average = 50.33”

Year Lakeland Bartow 1994 67.13 60 1995 48.47 60.31 1996 52.85 46.1 1997 58.14 60.2 1998 54.41 62.33 1999 48.66 42.29 2000 38.26 35.87 2001 57.67 49.56 2002 66.58 71.44 2003 60.13 63.83 94-03 Average 55.23” 55.19”DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 58 ‘missing mass.’ Chlorophyll a was calibrated using the BATHTUB calibration coefficient. Each lake/year combination was calibrated individually, but once the chlorophyll a calibration was set, it remained unchanged for all other BATHTUB simulations (background and TMDL development).

The phosphorous model that best fit Lake Hancock was Model 1, Second-Order, Available P model. The nitrogen model selected was Model 1, Second-Order, Available N model. The chlorophyll a model selected was Model 1, for P, N, Light and Flushing. Details regarding the selected models can be found in the BATHTUB Users Manual (U.S. Army Corps of Engineers, 1999; Walker, W.W., 2004). Figures 5.1 – 5.4 illustrate the measured, un-calibrated, and calibrated data for TN, TP, chlorophyll a , and TSI for the ten-year modeled period (1994 – 2003) for Lake Hancock.

Lake Hancock Total Nitrogen

0 1000 2000 3000 4000 5000 6000 7000 8000 9000

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 YearTN (ug/L)

TN-M easured TN-Uncalibrated TN-Calibrated



### Figure 5.1 Lake Hancock Total Nitrogen Measured, Un-Calibrated, and Calibrated Data from 1994 to 2003DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 59 Lake Hancock Total Phosphorus

0 100 200 300 400 500 600 700 800 900

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 YearTP (ug/L)

TP-M easured TP-Uncalibrated TP-Calibrated



### Figure 5.2 Lake Hancock Total Phosphorus Measured, Un-Calibrated, and Calibrated Data from 1994 to 2003

Lake Hancock Chlorophyll a

0 20 40 60 80 100 120 140 160 180

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 YearChla (ug/L)

Chla-M easured Chla-Uncalibrated Chla-Calibrated



### Figure 5.3 Lake Hancock Chlorophyll a Measured, Un-Calibrated, and Calibrated Data from 1994 to 2003DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 60 Lake Hancock TSI

30 40 50 60 70 80 90 100

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 YearTSI

TSI-M easured TSI-Uncalibrated TSI-Calibrated



### Figure 5.4 Lake Hancock TSI Measured, Un-Calibrated, and Calibrated Data from 1994 to 2003



### 5.1.3 Background Conditions

WAM Model
WAM was used to describe and evaluate the “natural land use background condition” for the entire Lake Hancock watershed, including Lower Saddle Creek. For this simulation, all current land uses were ‘reassigned’ to a mixture of Herbaceous, Prairies, Other Shrubs and Brush, Upland Coniferous Forest, Pine Flatwoods, Upland Hardwoods Forest, Hardwood Conifer Mix (the majority), Lakes, Inte rconnected Lakes, Reservoirs, Mixed Wetland Hardwoods, Streams and Lakes Swamps (bottoml ands), Wetland Coniferous Forest, Cypress, Wetland Forested Mix, Freshwater Marshes, Wet Prairies, Emergent Aquatic Vegetation, Inland Shores and Ephemeral Ponds. The current condition was maintained for all waterbody physical characteristics. From this point forward, the natural land use background will be referred to as “background.”

At first, the WAM was run with current rates of seepage around waterbodies and leakance from inside waterbodies. This resulted in such a large reduction in the total water flowing into the lakes that even with the significant reduction in external watershed loading, several lake/year combinations had higher concentrations of TN, TP, and chlorophyll a than under current conditions as the evaporation of 1. 32 meters nearly exceeded inflow and the lakes dried up. To account for this water loss in the background condition, seepage around the lakes was adjusted back to background conditions in the model and leakance was adjusted down (50 percent of current rate) until the lake stages and surface areas approximated current conditions. Even under this scenario the total water inflowing to the lakes under the background scenario was less than current conditions, particularly in the drier years (1996 and 2000). Again, this resulted in concentrations for some lake/year combinations being as great as they are under current conditions. In other words, the watershed model is indicating that under ‘natural land use’ dry conditions the lakes would have a trophic state similar to that ofDRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 61 today. Conversely, under average or wet conditi ons the natural land use trophic states were significantly less than current conditions.

BATHTUB Model

After achieving acceptable WAM background results, the BATHTUB model was run with no reduction in the total amount of missing mass (internal loading rate). As expected, with the reduction in total flow for the background condition and with no attenuation of the missing mass, many of the lake/year combinations did not improve. In fact, for the dry years the background condition was still worse than the current condition. In an effort to find the natural background, reductions in the missing mass were made. First, the BATHTUB model was used to identify the total external load of TN and TP under both the current condition and the background condition. Then the ratio of the change in external load between the background condition and the current condition (background/current) was applied to the missing mass (internal loading rate). This was called the attenuated case (A). This brought the in-lake trophic states down in the average and wet years, but many of the dry year lake trophic states remained higher in the background condition than in the current condition. As a result, the remaining missing mass was reduced until the worst case dry year trophic state was below the current conditions. This required an additional 75 percent reduction in the missing mass remaining after attenuation. The modeling abbreviations used in the tables, figures and report are explained below:

Abbreviations Used

L 100 = leakance at current conditions (calibrated model) L50 = leakance reduced from current conditions by 50 percent L0 = leakance reduced to near zero (0.01 m) PC = results from calibrated BATHTUB model IL = missing mass (used internal loading rate to achieve mass balance in model calibration) ILA = missing mass changed by the ratio of the change in external mass of background/current condition. IL50 = ILA plus an additional 50 percent reduction in missing mass IL75 = ILA plus an additional 75 percent reduction in missing mass ILNIL = all missing mass eliminated (loading rate = 0.0)


### 5.2 Selection of the TMDL Target

It should be recognized that the direct application of natural background as the target TSI would not allow for any assimilative capacity. The IWR uses as one measure of impairment in lakes, a 10 unit change in TSI from “historical” levels. This 10 unit increase is assumed to represent the transition of a lake from one trophic state (say mesotrophic) to another nutrient enriched condition (eutrophic). The Department has assumed that allowing a 5 unit increase in TSI over the natural background condition wo uld prevent a lake from becoming impaired (changing trophic states) and reserve 5 TSI units to allow for future changes in the basin and as part of the implicit margin of safety in establishing the assimilative capacity.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 62 After examining the background runs for Lake Hancock, it was decided that the scenario with leakance set at 50 percent of the current condition and the attenuated missing mass reduced by an additional 75 percent represented the natural land use background condition. These conditions resulted in a background TSI of 69.4. As has been Department practice, when acceptable background conditions can be establ ished, the target for TMDL development becomes the background TSI plus 5 TSI units (69.4 + 5 TSI units). Once the target TSI was established (a TSI of 74.4), the model was rerun with decreasing loads until the target TSI was met.
In order to complete the TMDL for Lake Hancock and Lower Saddle Creek, load reductions had to be proposed for the ten upstream lakes contributing to Lake Hancock. Based on achieving the TMDL targets for each year of the ten-year period of record, a long-term annual average TSI was set at 74.3 for the TMDL. The 0.1 TSI difference between the target and the established TMDL may be considered as additional margin of safety (MOS). The range in TSI TMDL targets was between 66.2 and 83.1. In addition, water quality in Lower Saddle Creek is directly influenced by the water quality in Lake Hancock. As a result of this direct influence, it is anticipated that achieving the TMDL for Lake Hancock will result in achieving water quality standards in Lower Saddle Creek.

The required annual average percent reduction for TN coming into Lake Hancock was 75.2 percent, with an allowable long-term annual average loading of 318,497.6 kg/year (702,167.1 lbs/year). The required annual average percent reduction for TP coming into the lake was 75.5, with an allowable long-term annual average loading of 101,749.6 kg/year (224,319.5 lbs/year).

The annual percent reductions ranged between 64.3 and 81.6 for TN and between 64.9 and 81.6 for TP. These reductions correspond to a range in loadings of 134,421.9 kg/year (296,349.6 lbs/year) to 476,505.4 kg/year (1,050,514.8 lbs/year) for TN, and between 14,430.8 kg/year (31,814.5 lbs/year) to 166,848.9 kg/year (367,838.9 lbs/year) for TP. Maintaining the long-term annual average loadings for TN and TP established in this TMDL should result in attaining the target long-term annual average TSI of 74.3 (the model TMDL target is 74.4).

Table 5.2 shows the TSI for the calibrated model (PC), the background model (IL75), the TMDL Target TSI, TMDL-TSI, and the percent reduction for Lake Hancock. The TSI for the calibrated model (PC), the background model (IL75), the TMDL Target TSI, TMDL-TSI, and the percent reduction for the ten lakes modeled for the Lake Hancock Basin are displayed in Appendix C

.
Table 5.3 shows the mass for TN and TP for the calibrated model, TMDL, and percent reductions for Lake Hancock. The mass for TN and TP for the ten lakes modeled for the Lake Hancock Basin are displayed in Appendix D

.
Table 5.4 shows the annual average concentrations for TN, TP, and chlorophyll a for Lake Hancock. Annual average concentrations for the ten lakes modeled for the Lake Hancock Basin are displayed in Appendix E

. Figures 5.5 – 5.8 show the TMDL target, calibrated data, and L50-IL75 for TN, TP, chlorophyll

a , and TSI for the ten-year modeled period (1994 – 2003) for Lake Hancock.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 63 Table 5.2 Lake Hancock TSI for PC, Background, TMDL Target, and TSI-Unit Percent Reduction

Lake Hancock TSI for Measured, PC, Background, TMDL Target, TMDL, and

TSI-unit Percent Reduction Based on Background L50-IL75

Year Color (PCU) Measured Calibrated Background IL75 Target IL75+5 TMDL Percent Reduction 1994 72.5 86.7 86.7 72.4 77.4 77.4 66.6 1995 87.5 86.0 86.0 68.1 73.1 73.1 75.0 1996 66.7 84.8 84.8 69.7 74.7 74.7 74.6 1997 53.3 82.2 82.2 61.9 66.9 66.7 75.0 1998 73.3 88.4 88.3 68.9 73.9 73.8 80.5 1999 240.0 94.4 94.5 78.1 83.1 83.1 82.0 2000 87.1 87.2 71.0 76.0 76.0 76.2 2001 79.2 79.2 61.2 66.2 66.2 74.0 2002 108.3 89.0 89.0 70.5 75.5 75.3 79.5 2003 100.3 90.4 90.4 72.1 77.1 77.1 80.6
Minimum 53.3 79.2 79.2 61.2 66.2 66.2 66.6 Maximum 240.0 94.4 94.5 78.1 83.1 83.1 82.0

Mean 100.2 86.8 86.8 69.4 74.4 74.3 76.4



### Table 5.3 Lake Hancock Mass for TN and TP for Calibrated Model, TMDL, and Percent Reduction

Lake Hancock Mass for TN and TP for Calibrated Model and TMDL, with Mass Percent Reductions (kg/year)

Year TN-MASS Calibrated TN-MASS TMDL TN-MASS % Reduction TP-MASS Calibrated TP-MASS TMDL TP-MASS % Reduction 1994 1,020,579.1 363,921.6 64. 3 323,799.6 113,600.8 64.9 1995 905,831.2 242,404.3 73.2 445,186.1 116,198.5 73.9 1996 1,454,898.7 383,852.0 73. 6 147,439.7 39,513.2 73.2 1997 791,641.4 206,396.3 73. 9 195,723.7 50,881.9 74.0 1998 1,510,080.9 307,309.1 79. 6 663,968.6 133,367.0 79.9 1999 2,575,794.6 475,038.2 81. 6 390,675.9 71,704.5 81.6 2000 698,685.9 171,653.8 75. 4 55,875.5 14,430.8 74.2 2001 479,896.6 134,421.9 72.0 637,466.0 166,848.9 73.8 2002 1,948,595.8 423,473.2 78. 3 699,984.0 146,013.7 79.1 2003 2,358,247.0 476,505.4 79. 8 839,590.6 164,936.8 80.4 Minimum 479,896.6 134,421. 9 64.3 55,875.5 14,430.8 64.9 Maximum 2,575,794.6 476,505.4 81.6 839,590.6 166,848.9 81.6

Mean 1,374,425.1 318,497.6 75. 2 439,971.0 101,749.6 75.5DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 200564Table 5.4 Lake Hancock Annual Average Concentrations for TN, TP, and ChlorophyllaLake HancockAnnual Average Concentrations for TN, TP, and Chlorophylla(μg/L)YearMeasuredTNCalibratedTNTMDLTNBackgroundTNMeasuredTPCalibratedTPTMDLTPBackgroundTPMeasuredChlaCalibratedChlaTMDLChlaBackgroundChla1994 3,290.5 3,290.7 1,748.31,479.3 411.5 412.0 233.8 107.5 141.6 141.8 100.3 73.61995 2,845.5 2,845.7 1,229.9 963.4 453.5452.7 219.2 114.2 160.4 159.4 93.1 67.61996 4,742.3 4,741.4 2,190.31,678.6 320.3 319.8 154.8 103.8 91.0 91.1 61.0 47.21997 2,257.8 2,257.2 888.7 684.7 256.7 256.1 117.2 62.7 133.1 133.3 62.8 40.81998 3,521.0 3,521.7 1,306.81,025.4 511.0 511.1 215.7 117.8 162.2 161.6 93.5 68.41999 7,644.5 7,643.9 2,975.72,212.3 637.0 636.9 258.9 172.2 160.2 160.4 113.9 90.42000 4,840.0 4,839.4 2,139.11,570.9 297.5 297.1 139.1 102.5 130.2 130.5 79.4 59.42001 2,760.0 2,760.0 1,225.4 938.9 767.0767.7 379.3 211.0 65.7 64.9 36.2 26.82002 4,050.5 4,050.9 1,561.91,211.4 525.7 524.7 224.5 131.4 143.6 143.2 88.3 66.22003 4,573.6 4,573.8 1,754.11,340.7 581.6 581.3 244.0 138.8 145.5 145.6 95.6 71.7Minimum 2,257.8 2,257.2 888.7 684.7 256.7 256.1 117.2 62.7 65.7 64.9 36.2 26.8Maximum 7,644.5 7,643.9 2,975.7 2,212.3767.0 767.7 379.3 211.0162.2 161.6 113.9 90.4Mean 4,052.6 4,052.5 1,702.0 1,310.6 476.2 475.9 218.7126.2 133.4 133.2 82.4 61.2DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 65 Lake Hancock Total Nitrogen

0 1000 2000 3000 4000 5000 6000 7000 8000 9000

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 YearTN (ug/L)

TN-TM DL TN-L50-IL75 TN-PC



### Figure 5.5 Lake Hancock Total Nitrogen Target TMDL, L50-IL75, and Background Calibration from 1994 to 2003

Lake Hancock Total Phosphorus

0 100 200 300 400 500 600 700 800 900

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 YearTP (ug/L)

TP-TM DL TP-L50-IL75 TP-PC



### Figure 5.6 Lake Hancock Total Phosphorus Target TMDL, L50-IL75, and Background Calibration from 1994 to 2003DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 66 Lake Hancock Chlorophyll a

0 20 40 60 80 100 120 140 160 180

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 YearChla (ug/L)

CHLA-TM DL CHLA-L50-IL75 CHLA-PC



### Figure 5.7 Lake Hancock Chlorophyll a Target TMDL, L50-IL75, and Background Calibration from 1994 to 2003

Lake Hancock TSI

30 40 50 60 70 80 90 100

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 YearTSI

TSI-TM DL TSI-L50-IL75 TSI-PC



### Figure 5.8 Lake Hancock TSI Target TMDL, L50-IL75, and Background Calibration from 1994 to 2003DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 67 5.3 Critical Conditions

The estimated assimilative capacity was based on annual average conditions (i.e., values from all four seasons in a calendar year) rather than critical/seasonal conditions because (a) the methodology used to determine the assimilative capacity does not lend itself very well to short-term assessments, (b) the Department is generally more concerned with the net change in overall primary productivity in the segment, which is better addressed on an annual basis, and (c) the methodology used to determine impairment is based on an annual average and requires data from all four quarters of a calendar year.



### 5.4 Wasteload Allocation

There are two NPDES facilities that discharge into Lake Lena Run, a tributary to Lake Hancock. The City of Auburndale Allred WWTF (FL0021466-004-DW1P/RA) operates a 1.4 MGD annual average daily flow (AADF) that must provide advanced secondary treatment for any discharge into Lake Lena Run. The facility is permitted to discharge 0.65 mgd on a monthly average basis to Lake Lena Run. The facility has a permit limit for total nitrogen of 6.0 mg/L as a monthly average and a report only limit for total phosphorus.
The second facility is Florida Distillers Company-Auburndale, (FL0003051-003-IWB). The facility is permitted to discharge up to 0.5 mgd (monthly average) to Lake Lena Run through outfall D002. The permit includes a daily maximum total nitrogen limit of 4.4 mg/L and a report only limit for total phosphorus.

Several different scenarios were examined to evaluate the contribution of the two facilities to the flow and loadings coming into Lake Hancock. The first scenario was for the current condition used for calibration. This case is referred to as Point Sources Predicted Calibration (PSPC). The flows and concentrations used were based on the monthly average data contained in the EPA NPDES database, which is the Permit Compliance System (PCS). This set of information was used to calibrate the WAM model and is the base case against which the other two scenarios will be evaluated. The second case was for the two facilities at their respective permit limits for flows and concentrations. This set of data was provided by staff from EPA Region IV. This case is referred to as Point Sources Maximum (PSMAX). The last scenario was with both point sources completely removed. This case is referred to as No Point Sources (NoPS).

Table 5.5 contains the flow in cubic hectometers per year (CHMY) for each source. Sources include tributary inflow and advective inflow. The tributary inflow is generated within the WAM model, and the advective terms are generated within the BATHTUB model. The advective terms reflect the net discharge from one BATHTUB segment into another and are derived from water-balance calculations. The water balances in BATHTUB are expressed as a system of simultaneous linear equations that are solved via a matrix inversion to estimate the advective out-flow from each model segment. The advective inflow to Lake Hancock represents the sum of all the advective outflows from the upstream lakes.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 68 Table 5.5 Flow in Cubic Hectometers Per Year for Each Source

Year PSPCTRIBFlow (hm3/yr) PSPCADVFlow (hm3/yr) PSPCTOTFlow (hm3/yr) PSMAXTRIBFlow (hm3/yr) PSMAXADVFlow (hm3/yr) PSMAXTOTFlow (hm3/yr) NoPSTRIBFlow (hm3/yr) NoPSADVFlow (hm3/yr) NoPSTOTFlow (hm3/yr) 1994 84.3192 30.9393 115.2585 83.6379 30. 9393 114.5772 82.0881 30.9393 113.0274 1995 92.7466 34.9953 127.7419 92.5607 34. 9954 127.5561 91.0104 34.9954 126.0058 1996 66.9599 17.9993 84.9593 67.3612 17. 9994 85.3606 65.818 17.9994 83.8174 1997 127.8228 50.2292 178.0521 127.8971 50. 2293 178.1264 126.3497 50.2293 176.5791 1998 108.4174 35.7243 144.1416 108.556 35. 7243 144.2803 107.0008 35.7242 142.725 1999 56.474 12.4693 68.9433 56.8721 12.469 3 69.3413 55.3333 12.4693 67.8026 2000 45.8525 5.5804 51.4329 46.377 5. 5804 51.9573 44.8298 5.5804 50.4102 2001 66.6592 13.9542 80.6135 67.2088 13. 9542 81.163 65.6655 13.9542 79.6197 2002 115.5383 46.7394 162.2776 115.8947 46. 7394 162.634 114.3425 46.7395 161.0819 2003 106.6242 36.4613 143.0855 106.8131 36. 4613 143.2744 105.2606 36.4613 141.7219
Minimum 45.8525 5.5804 51.4329 46.377 5.5804 51.9573 44.8298 5.5804 50.4102 Maximum 127.8228 50.2292 178.0521 127.8971 50.2293 178.1264 126.3497 50.2293 176.5791

Mean 87.1414 28.5092 115.6506 87.3178 28. 5092 115.8271 85.7699 28.5092 114.2791 Point Sources at Current Conditions (PSPC) Point Sources at Permit Limits (PSMAX) No Point Sources (NoPS)DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 69 Table 5.6 shows the difference between the calibrated model total flows into the lake and the PSMAX and NoPS scenarios. From the table it can be seen that on average, the current condition has slightly less overall flow than with the two facilities operating at the monthly average flows specified in the permits. At the permitted monthly average flow, the annual average inflow to the lake increased by only 0.25 percent over the current condition. The elimination of both facilities would reduce the annual average flow into the lake by 1.30 percent (1.37 CHMY).

Table 5.6 Difference between PSPC and PSMAX and PSPC and NoPS Flow (hm3/yr)

Year PSPC-PSMAX Flow Total

(hm3/yr) PSPC-NoPS Flow Total

(hm3/yr) PSPC-PSMAX Flow Total

(hm3/yr) PSPC-NoPS Flow Total

(hm3/yr) %change %change 1994 0.68 2.23 0.59 1.94 1995 0.19 1.74 0.15 1.36 1996 -0.4 1.14 -0.47 1.34 1997 -0.07 1.47 -0.04 0.83 1998 -0.14 1.42 -0.1 0.98 1999 -0.4 1.14 -0.58 1.65 2000 -0.52 1.02 -1.02 1.99 2001 -0.55 0.99 -0.68 1.23 2002 -0.36 1.2 -0.22 0.74 2003 -0.19 1.36 -0.13 0.95
Minimum -0.55 0.99 -1.02 0.74 Maximum 0.68 2.23 0.59 1.99

Mean -0.18 1.37 -0.25 1.3



### Table 5.7 shows the results for TP for each of the scenarios described for flow. The various sources of TP include tributary inflow, advective inflow, and internal loading. The mass attributed to internal loading is described in the section on model calibration. Recall, it is not just mass from internal recycling, but is actually the sum of all the TP mass not otherwise accounted for in the mass balance (i.e. the missing TP mass).DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 200570Table 5.7 Total Phosphorus Mass (kg/year)YearPSPCTP-TRIBPSPCTP-ADVPSPCTP-ILPSPCTP-TOTPSMAXTP-TRIBPSMAXTPADVPSMAXTP-ILPSMAXTP-TOTNoPSTP-TRIBNoPSTP-ADVNoPSTP-ILNoPSTP-TOT1994 12,901.6 13,017.8 298,084.1 324,003.612,845.1 13,017.8 297,866.9 323,729.812,513.5 13,017.8 297,455.4 322,986.71995 15,015.7 14,260.5 416,194.8 445,471.015,053.8 14,260.5 416,129.9 445,444.214,722.0 14,260.5 415,842.7 444,825.11996 11,013.8 7,923.4 128,590.5 147,527.811,191.6 7,923.5 128,610.0 147,725.110,860.9 7,923.5 128,534.8 147,319.21997 23,884.2 19,930.5 152,013.0 195,827.723,928.7 19,930.5 152,044.3 195,903.523,596.7 19,930.5 151,819.6 195,346.81998 19,501.5 20,041.7 624,853.1 664,396.319,546.7 20,041.7 624,877.3 664,465.819,215.2 20,041.7 624,631.9 663,888.81999 9,798.8 6,161.3 374,972.4 390,932.59,883.8 6,161.3 375,111.8 391,156.9 9,553.9 6,161.3 374,571.6 390,286.82000 8,443.0 5,335.3 42,126.1 55,904.38,543.6 5,335.3 42,150.5 56,029.38,211.5 5,335.3 42,061.2 55,608.02001 12,962.3 9,387.4 615,537.7 637,887.413,084.5 9,387.4 616,012.3 638,484.212,753.5 9,387.4 614,734.9 636,875.82002 19,492.5 19,122.8 661,821.8 700,437.019,579.5 19,122.8 662,076.4 700,778.719,247.8 19,122.8 661,432.9 699,803.42003 18,321.6 11,908.5 809,914.9 840,145.018,350.1 11,908.5 809,967.5 840,226.118,019.2 11,908.5 809,608.1 839,535.9Minimum 8,443.0 5,335.3 42,126.1 55,904.3 8,543.6 5,335.3 42,150.5 56,029.3 8,211.5 5,335.3 42,061.2 55,608.0Maximum 23,884.2 20,041.7 809,914.9 840,145.0 23,928.7 20,041.7 809,967.5 840,226.1 23,596.7 20,041.7 809,608.1 839,535.9Mean 15,133.5 12,708.9 412,410.8 440,253.2 15,200.7 12,708.9 412,484.7 440,394.414,869.4 12,708.9 412,069.3 439,647.6Point Sources at Current Conditions (PSPC)Point Sources at Permit Limits (PSMAX)No Point Sources (NoPS)DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 71 Table 5.8 shows the differences between the calibrated model total TP mass (kg/y) input into the Lake and both the PSMAX and NoPS scenarios. From the gable it can be seen that on average, the current condition has sli ghtly less overall TP mass than with the two facilities operating at the monthly average concentrations derived from the PCS data. At the permitted monthly average flow, the annual average TP mass inflowing to the Lake increased by only 0.05 percent (141.1 kg/y). The elimination of both facilities would reduce the annual average TP mass into the Lake by 0.19 percent (605.6 kg/y).

Table 5.8 Total Phosphorus Mass (kg/year) Difference between PSPC and PSMAX and PSPC and NoPS

Year PSPC-PSMAX Difference in TP as kg/year PSPC-NoPS Difference in TP as kg/year PSPC-PSMAX Difference in TP as percent PSPC-NoPS Difference in TP as percent 1994 273.7 1016.8 0.08 0.31 1995 26.8 645.8 0.01 0.14 1996 -197.3 208.6 -0.13 0.14 1997 -75.8 480.9 -0.04 0.25 1998 -69.5 507.5 -0.01 0.08 1999 -224.4 645.7 -0.06 0.17 2000 -125 296.4 -0.22 0.53 2001 -596.8 1011.6 -0.09 0.16 2002 -341.7 633.6 -0.05 0.09 2003 -81.1 609.1 -0.01 0.07
Minimum -596.8 208.6 -0.22 0.07 Maximum 273.7 1016.8 0.08 0.53 Average -141.1 605.6 -0.05 0.19



### Table 5.9 shows the results for TN for each of the scenarios described for flow. The various sources of TN include tributary inflow, advective inflow, and internal loading. The mass attributed to internal loading is described in the section on model calibration. Recall, it is not just mass from internal recycling, but is actually the sum of all the TN mass not otherwise accounted for in the mass balance (i.e. the missing TN mass).DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 200572Table 5.9 Total Nitrogen Mass (kg/year)YearPSPCTN-TRIBPSPCTN-ADVPSPCTN-ILPSPCTN-TOTPSMAXTN-TRIBPSMAXTN-ADVPSMAXTN-ILPSMAXTN-TOTNoPSTN-TRIBNoPSTN-ADVNoPSTN-ILNoPSTN-TOT1994 95,809.9 75,027.0 850,324.1 1,021,161.0 99,941.4 75,026.9 849,704.5 1,024,672.9 90,738.9 75,026.9 848,530.6 1,014,296.31995 104,720.5 61,645.1739,972.1 906,337.7 108,193.2 61,645.1 739,856.8909,695.1 98,999.9 61,645.1 739,346.2 899,991.31996 70,727.9 39,596.6 1,345,495.3 1,455,819.877,139.8 39,596.6 1,345,699.8 1,462,436.368,159.9 39,596.71,344,913.1 1,452,669.81997 134,996.1 122,453.1534,558.1 792,007.3 141,163.9 122,453.2 534,668.1798,285.3 132,002.4 122,453.3 533,878.1 788,333.71998 109,122.0 83,581.5 1,318,279.8 1,510,983.3114,354.6 83,581.5 1,318,330.9 1,516,267.0 105,156.2 83,581.4 1,317,813.1 1,506,550.81999 62,991.0 39,803.0 2,474,694.5 2,577,488.570,235.5 39,802.9 2,475,614.5 2,585,653.061,372.4 39,803.02,472,049.0 2,573,224.32000 59,478.1 24,454.2615,174.7 699,107.0 66,778.6 24,454.1 615,530.6706,763.3 58,011.6 24,454.2 614,226.9 696,692.72001 78,445.6 64,208.1337,473.9 480,127.6 85,764.2 64,208.0 337,734.1487,706.3 76,920.5 64,207.9 337,033.8 478,162.12002 116,668.0 162,759.0 1,670,312.0 1,949,739.0123,696.4 162,759.01,670,954.9 1,957,410.3 114,567.2 162,759.3 1,669,330.6 1,946,657.12003 109,343.0 88,903.1 2,161,480.5 2,359,726.5114,456.2 88,903.0 2,161,620.8 2,364,980.0 105,257.8 88,903.0 2,160,661.8 2,354,822.5Minimum 59,478.1 24,454.2 337,473.9 480,127.6 66,778.6 24,454.1 337,734.1 487,706.3 58,011.6 24,454.2 337,033.8 478,162.1Maximum 134,996.1 162,759.0 2,474,694.5 2,577,488.5 141,163.9 162,759.0 2,475,614.5 2,585,653.0 132,002.4162,759.3 2,472,049.02,573,224.3Average 94,230.2 76,243.1 1,204,776.5 1,375,249.8 100,172.4 76,243.0 1,204,971.5 1,381,386.9 91,118.7 76,243.1 1,203,778.3 1,371,140.0Point Sources at Current Conditions (PSPC)Point Sources at Permit Limits (PSMAX)No Point Sources (NoPS)DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 73 Table 5.10 shows the differences between the calibrated model total TN mass (kg/y) input into the Lake and both the PSMAX and NoPS scenarios. From the table, it can be seen that on average, the current condition has slightly less overall TN mass than with the two facilities operating at the monthly average concentrations derived from the PC S data. At the permitted monthly average flow, the annual average TN mass inflowing to the lake increased by only 0.59 percent (6137.2 kg/y). The elimination of both facilities would reduce the annual average TN mass into the lake by 0.36 percent (4109.7 kg/y).

Table 5.10 Total Nitrogen Mass (kg/year) Difference between PSPC and PSMAX and PSPC and NoPS

Year PSPC-PSMAX Difference in TN as kg/year PSPC-NoPS Difference in TN as kg/year PSPC-PSMAX Difference in TN as percent PSPC-NoPS Difference in TN as percent 1994 -3511.9 6864.7 -0.34 0.67 1995 -3357.4 6346.4 -0.37 0.7 1996 -6616.5 3150 -0.45 0.22 1997 -6278 3673.6 -0.79 0.46 1998 -5283.8 4432.5 -0.35 0.29 1999 -8164.5 4264.3 -0.32 0.17 2000 -7656.3 2414.3 -1.1 0.35 2001 -7578.7 1965.5 -1.58 0.41 2002 -7671.3 3081.9 -0.39 0.16 2003 -5253.5 4904 -0.22 0.21
Minimum -8164.5 1965.5 -1.58 0.16 Maximum -3357.4 6864.7 -0.22 0.7 Average -6137.2 4109.7 -0.59 0.36



### To summarize, the annual average difference between operating the facilities at current conditions and at their respective permit limits was a 0.25 percent increase in total flow coming into the lake in combination with a 0.05 percent increase in TP mass and a 0.59 percent increase in TN mass. The annual average difference between the current condition and elimination of the two facilities was a 1.3 percent reduction in total flow coming into the lake in combination with a 0.19 percent reduction in TP mass and a 0.36 percent reduction in TN mass. Preliminary modeling with BATHTUB indicates that the reduction in flow to the lake resulting from elimination of the discharge from both facilities had an adverse effect on the lake that more than countered the impact of the mass reductions. At this time, our preliminary results indicate that the annual average TSI of the lake would increase by 0.2 TSI units if the two facilities were eliminated. Therefore, the WLA for the two facilities is to maintain their currently permitted loads to the lake (note: the current permits do not actually include load limits for TN and TP, and t hese limits will need to be added to ensure that there are no increases in TP or TN loadings to the lake).DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 74 

# Chapter 6: DETERMINATION OF THE TMDL

6.1 Expression and Allo cation of the TMDL

A TMDL can be expressed as the sum of all point source loads (wasteload allocations or WLAs), nonpoint source loads (load allocations or LAs), and an appropriate margin of safety (MOS) that takes into account any uncertainty about the relationship between effluent limitations and water quality:
As mentioned previously, the WLA is broken out into separate subcategories for wastewater discharges and stormwater discharges regulated under the NPDES Program:

TMDL ≅ ∑

 WLAs wastewater 

### + ∑

 WLAs NPDES Stormwater 

### + ∑

 LAs + MOS

It should be noted that the various components of the TMDL equation may not sum up to the value of the TMDL because a) the WLA for NPDES stormwater is typically based on the percent reduction needed for nonpoint sources and is accounted for within the LA, and b) TMDL components can be expressed in different terms [for example, the WL A for stormwater is typically expressed as a percent reduction and the WLA for wastewater is typically expressed as a mass per day]. WLAs for stormwater discharges are typically expr essed as “percent reduction” because it is very difficult to quantify the loads from MS4s (given the numerous discharge points) and to distinguish loads from MS4s from other nonpoint sources (g iven the nature of stormwater transport). The permitting of stormwater discharges is also different than the permitting of most wastewater point sources. Because stormwater discharges cannot be centrally collected, monitored and treated, they are not subject to the same types of effluent limitations as wastewater facilities, and instead are required to meet a performance standard of pr oviding treatment to the “maximum extent practical” through the implementation of Best Management Practices.
This approach is consistent with federal regulations [40 CFR § 130.2(I)], which state that TMDLs can be expressed in terms of mass per time (e.g. pounds per day), toxicity, or other appropriate

measure . The TMDL for Lake Hancock is expressed in terms of pounds (lbs) per year (converted from kilograms per year as shown in Chapter 5, Table 5.3) and percent reductions, and represent the long-term annual average load of TN and TP Lake Hancock can assimilate and maintain the Class III narrative nutrient criterion (see Table 6.1 ).

Table 6.1 Lake Hancock and Lower Saddle Creek TMDL Load Allocations

WLA WBID Parameter Wastewater (lbs/year) Stormwater (% reduction) LA (lbs/year) MOS TMDL (lbs/year) Percent Reduction

1623L, 1623K TN (*1) 75.2 

### 702,167 Implicit 

### 702,167 75.2

1623L, 1623K TP (*1) 75.5 

### 224,320 Implicit 

### 224,320 75.5

(*1) Note: permits for the two facilities should be modified to include monthly average loading limits for TN and TP used in the scenario PSMAX.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 75 6.2 Load Allocation (LA)

The required long-term annual average allowable LA is 702,167.1 lbs/year (1,923.8 lbs/day) for TN and 224,319.5 lbs/year (614.6 lbs/day) for TP. This corresponds to reductions from the existing loadings of 75.2 percent for TN and 75.5 percent for TP. Maintaining the long-term annual average loadings for TN and TP established as this TMDL should result in attaining the target lake annual average TSI of 74.4 and maintain water quality standards in Lower Saddle Creek. It should be noted that the LA may include loading from stormwater discharges regulated by the Department and the Water Management District that are not part of the NPDES Stormwater Program (see Appendix A).


### 6.3 Wasteload Allocation (WLA)

NPDES Wastewater Discharges
As noted in Chapter 4, Section 4.2.1, there are two active National Pollutant Discharge Elimination System (NPDES) per mitted facilities located within the Lake Lena Run/Creek watershed. Lake Lena Run is a part of the Lake Lena and Lake Lena Run sub-basin modeled for the Lake Hancock Basin. Based on the results discussed in Section 5.4, the annual average difference between operating the facilities at current conditions and at their respective permit limits was a 0.25 percent increase in total flow coming into the Lake in combination with a 0.05 percent increase in TP mass and a 0.59 percent increase in TN mass.

The annual average difference between the current condition and elimination of the two facilities was a 1.3 percent reduction in total flow coming into the Lake in combination with a 0.19 percent reduction in TP mass and a 0.36 percent reduction in TN mass. Preliminary modeling with BATHTUB indicates that the reduction in flow resulting from elimination of the two facilities had an adverse effect on the lake that more than countered the impact of the mass reductions. At this time, results indicate that the annual average TSI of the lake would increase by 0.2 TSI units if the two facilities were eliminated. Therefore, the WLA for the two NPDES facilities is to maintain their currently permitted loads, such that there are no increases in TP or TN loadings to the lake over those modeled in the scenario PSMAX discussed in Section 5.4

. NPDES Stormwater Discharges
The wasteload allocation for stormwater discharges is a 75.2 percent reduction in loading for TN and 75.5 percent for TP, which is the required percent reduction in nonpoint sources. It should be noted that any MS4 permittee will only be responsible for reducing the loads associated with stormwater outfalls for which it owns or otherwise has responsible control, and is not responsible for reducing other nonpoint source loads within its jurisdiction.


### 6.4 Margin of Safety (MOS)

TMDLs must address uncertainty issues by incorporating a MOS into the analysis. The MOS is a required component of a TMDL and accounts for the uncertainty about the relationship between pollutant loads and the quality of the receiving waterbody [Clean Water Act, Section 303(d) (1) (c)]. Considerable uncertainty is usually inherent in estimating nutrient loading from nonpoint sources, as well as predicting water quality response. The effectiveness of management activities (e.g., stormwater management plans) in reducing loading is also subject to uncertainty.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 76 The MOS can either be implicitly accounted for by choosing conservative assumptions about loading or water quality response, or explicitly accounted for during the allocation of loadings. Consistent with the recommendations of the Allocation Technical Advisory Committee (Florida Department of Environmental Protection, February 2001), an implicit margin of safety (MOS) was used in the development of the Lake Hancock and Lower Saddle Creek TMDLs. An implicit MOS was used for Lake Hancock because the TMDL was based on the conservative decisions associated with a number of the modeling assumptions and allowing for a10 TSI unit increase (5 TSI units above natural background conditions and an additional 5 TSI units to allow for future changes in the watershed) in determining the assimilative capacity (i.e., loading and water quality response) for the lake.



### 6.5 Lower Saddle Creek

Because Lower Saddle Creek serves mainly as a conveyance system/primary outfall from Lake Hancock, loadings to the creek from Lake Hanco ck are believed to be the primary cause of the impairments to the creek. Thus, Lower Saddle Creek is expected to attain water quality standards following implementation of the Lake Hancock TMDL because the lake TMDL will require a 75.2 percent reduction in TN and a 75.5 percent reduction in TP loadings (see Table 6.1 ).DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 77 

# Chapter 7: NEXT STEPS: IMPLEMENTATION PLAN DEVELOPMENT AND BEYOND

Following adoption of this TMDL by rule, the next step in the TMDL process is to develop an implementation plan for the TMDL, which will be a component of the Basin Management Action Plan for Lake Hancock and Lower Saddle Creek (and the Lake Hancock Basin). This document will be developed in cooperation with local stakeholders and will attempt to reach consensus on more detailed allocations and on how load reductions will be accomplished.

The Basin Management Action Plan (BMAP) will include:

• Appropriate allocations among the affected parties.

• A description of the load reduction activities to be undertaken.

• Timetables for project implementation and completion.

• Funding mechanisms that may be utilized.

• Any applicable signed agreements.

• Local ordinances defining actions to be taken or prohibited.

• Local water quality standards, permits, or load limitation agreements.

• Monitoring and follow-up measures.

It should be noted that TMDL development and implementation is an iterative process, and this TMDL will be re-evaluated during the BMAP development process and subsequent Watershed Management cycles. The Department acknowledges the uncertainty associated with TMDL development and allocation, particularly in estimates of nonpoint source loads and allocations for NPDES stormwater discharges, and fully expects that it may be further refined or revised over time. If any changes in the estimate of the assimilative capacity AND/OR allocation between point and nonpoint sources are required, the rule adopting th is TMDL will be revised, thereby providing a point of entry for interested parties.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 78 

# References

Abtew, Wossenu, 1992. An Atlas of the Lower Kissimmee and Lake Istokpoga Surface Water Management Basins . South Florida Water Management District (SFWMD) Technical Memorandum DRE # 313.

Baniukiewicz, A. and D. Gilbert, 2004. Nutrient Total Maximum Daily Load for Lake Hunter, Polk County, Florida. Florida Department of Environmental Protection, Division of Water Resource Management, Watershed Assessment Section, Tallahassee, Florida, September, 2004.
BCI Engineers & Scientists, Inc. 2005. Lake Hancock Lake Level Modification Preliminary Evaluation, Final Report . Prepared for the Southwest Florida Water Management District, Brooksville, Florida.
Bottcher, A.B, N.B. Pickering, and A.B. Cooper, 1998. EAAMOD-FIELD: A Flow and Phosphorous Model for High Water Tables . Proceedings of the 7th Annual Drainage Symposium. American Society of Agricultural Engineers, St. Joseph, MI.

Bottcher, A.B., J.G. Hiscock, and B.M. Jacobson, 2002 . Watershed Assessment Model (WAM), a Geographic Information System (GIS) Appr oach to Watershed Assessment Modeling . Proceeding of the Watershed 2002 Pre-Conference Modeling Workshop. Ft. Lauderdale, FL. Publisher: Water Environment Federation. Alexandria, VA.
Brenner, M., T. Whitmore, M. S. Flannery, and M. W. Binford, 1993. Paleolimnological Methods for Defining Target Conditions in Lake Restoration: Florida Case Studies. Journal series No. R-01700 of the Florida Agricultural Experiment Station.

Brenner, M., T. Whitmore, J. H. Curtis, and C. L. Schelske, 1995. Historical Ecology of a Hypereutrophic Florida Lake. Journal series No. R-04021 of the Florida Agricultural Experiment Station.

Brenner, M., T. Whitmore, J. H. Curtis, and D. A. Hodell, 2002. Lake Hancock: A Multi-Proxy Reconstruction of Past Trophic State Conditions Final Report. Prepared for the Southwest Florida Water Management District. Published by the Department of Geological Sciences and the Department of Fisheries and Aquatic Sciences, Un iversity of Florida, Gainesville, Florida, December, 2002.

Bromwell and Carrier, Inc., 1990. Construction Permit Application for the Regional Drainage Restoration Project (Plan C). Southwest Florida Water Management District, Brookesville, Florida.

Camp, Dresser, & McKee, 2002. Lake Hancock Restoration Management Plan, Final Report. Prepared for the Polk County Board of Commissi oners and Florida Department of Environmental Protection. Prepared by CDM, January, 2002.

City of Lakeland, 2001. City of Lakeland Lakes Water Quality Report, 1988 to 2000. Prepared by the City of Lakeland, Public Works Department, Lak es and Stormwater Division, Lakeland, Florida, August 2001. Web site available at http://www.lakelandgov.net/publicworks/la kes/files/CC61F2B4E0FF48779DC9B308EFCF5B2E.pdf

.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 79 City of Lakeland, 2005. Lakeland 2005 Capitol Improvement Projects. Prepared by the City of Lakeland, Public Works Department, Lakes and Stormw ater Division, Lakeland, Florida. Available at http://www.lakelandgov.net/publicworks/la kes/files/023793F01E65428D 9DBEBA1E0F14A82B.pdf

. Chew, R. L., 1974. Early Life History of the Florida Largemouth Bass. Dingell-Johnson Project F24-R. Fishery Bulletin #7, Florida Game and Freshwater Fish Commission, Tallahassee, Florida.
Dixit, S.S., J.P. Smol, J.C. Kingston, and D.F. Charles, 1992. Diatoms: powerful indicators of environmental change . Environmental Science and Technology 26: 23-33.

Environmental Research & Design, Inc., 2005. Physical and chemical characterization of Lake Hancock surface water . Prepared for Parsons Water and Infrastructure. Prepared by ERD Inc., Orlando, Florida, March, 2005.

___, 2002. Lake Morton Water Quality Diagnostic Evaluation . Prepared by ERD Inc., Orlando, Florida, December, 2002.

___, 1999. Lake Hancock Water and Nutrient Budget and Water Quality Improvement Project: Final Report . Prepared for the Southwest Florida Water Management District (SWFWMD) SWIM Program. Prepared by ERD Inc., Orlando, Florida, December, 1999.

Florida Department of Environmental Protection, February 2001. A Report to the Governor and the Legislature on the Allocation of Total Maximum Daily Loads in Florida. Florida Department of Environmental Protection, Allocation Technical Ad visory Committee, Division of Water Resource Management, Bureau of Watershed Management, Tallahassee, Florida.

—, April 2001. Chapter 62-302, Surface Water Quality Standards, Florida Administrative Code ( F.A.C. ), Florida Department of Environmental Protection, Division of Water Resource Management, Bureau of Watershed Management, Tallahassee, Florida.

—, April 2001. Chapter 62-303, Identification of Impaired Surface Waters Rule (IWR), Florida Administrative Code . Florida Department of Environmental Protection, Division of Water Resource Management, Bureau of Watershed Management, Tallahassee, Florida.
—, June 2004. Division of Water Resource Management, Bureau of Information Systems, Geographic Information Systems Section, Florid a Department of Environmental Protection, Tallahassee, Florida. Available at http://www.dep.state.fl.us/gis/contact.htm

—, October 2004. Group 3 Sarasota Bay and Peace and Myakka Rivers Water Quality Assessment Report. Florida Department of Environmental Protection, Division of Water Resource Management, Watershed Assessment Section, Southwest District, Group 3 Basin, Tallahassee, Florida.

—, June 2005. Wastewater Facility Regulation (WAFR), Facility Detail Report. Division of Water Resource Management, Florida Department of Envi ronmental Protection, Tallahassee, Florida. Available at http://www.dep.state.fl.us/water/wastewater/index.htm

. Florida Department of Health, July 2004. Florid a Department of Health web site. Available at http://www.doh.state.fl.us/ ; or http://www.doh.state.fl.us/environmen t/OSTDS/statistics/ostdsstatistics.htm

.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 80 Florida Department of Transportation, 1999 . Florida Land Use, Cover and Forms Classification Systen (FLUCCS) . Florida Department of Transportation Thematic Mapping Section.

Friedemann, M. and Hand, J., 1989. Typical Water Quality Values for Florida Lakes, Streams, and Estuaries. Florida Department of Environmental Regul ation, Bureau of Surface Water Management, Standards and Monitoring Section, Tallahassee, Florida.

FWRA, 1999. Florida Watershed Restoration Act, Chapter 99-223, Laws of Florida.
Gao, X., D. Gilbert, and W. Magley, 2005. Nutrient Total Maximum Daily Load for Alachua Sink, Alachua County, Florida . Florida Department of Environmental Protection, Division of Water Resource Management, Watershed Assessment Sect ion, Tallahassee, Florida, February, 2005.

Gao, X., 2005. Nutrient and Unionized Ammonia Total Maximum Daily Loads for Lake Jesup, Seminole County, Florida . Florida Department of Environmental Protection, Division of Water Resource Management, Watershed Assessment Sect ion, Tallahassee, Florida, August, 2005.

Guardo, Mariano, 1992. An Atlas of the Upper Kissimmee Surface Water Management Basins

. Southwest Florida Water Management District (SWFWMD) Technical Memorandum DRE # 309.

Hammett, K. M., L. J. Snell and B. F. Joyner, 1981 . Hydrologic Description of Lake Hancock, Polk County, Florida . WRI Open File Report 81-131. Prepared by USGS in cooperation with the Southwest Florida Water Management District

Harper, H.H., 1994. Stormwater Loading Rate Parameters for Central and South Florida. Environmental Research and Design, Inc., Orlando, Florida, October, 1994.

Harper, H.H. and Baker, D. M., 2003. Evaluation of Alternative Stormwater Regulations for Southwest Florida, Final Report. Environmental Research and Design, Inc., Orlando, Florida, September, 2003.

Harper, H.H., J.L. Herr, and D.M. Baker. 1999. Lake Hancock Water and Nutrient Budget and Water Quality Improvement Project. Final Report to the Southwest Florida Water Management District. Environmental Research and Design, Inc., Orlando, Florida, December, 1999.

Huber, W.C., P.L. Brezonik, J.P. Heaney, R.E. Dickinson, S.D. Preston., D.S. Dwornik, and M.A. DeMaio, 1982 . A classification of Florida lakes . Report ENV-05-82-to the Florida Department of Environmental Regulation, Tallahassee, FL. Keith and Schnars, 2003. Saddle Creek Watershed Management Program Task II - Watershed Management Plan . Polk County Board of County Commissioners and the Southwest Florida Water Management District, Lakeland, Florida.
Jacobson, Barry M., Adelbert B. Bottcher, Nigel B. Pickering, and Jeffrey G. Hiscock, 1998. Unique routing algorithm for watershed assessment model. ASAE Paper No. 98-2237. Am. Soc. of Agr. Eng., St. Joseph, MI 49085.

Knisel, W. G., 1993. GLEAMS: Ground Water Loading Effects of Agricultural Management Systems. UGA-CPES-BAED Publication no. 5.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 81 National Weather Service, 2004. National Weather Service, National Climatic Data Center, Climate Interactive Rapid Retrieval User System (CIRRU S) Database hosted by the Southeast Regional Climate Center web site. Available at http://www.dnr.state.sc.us/pls/cirrus/cirrus.login.

Patton and Associates, Inc., June, 1980 . Geologic Observations on the Ordinary High Water Line of Lake Hancock, Polk County, Florida. Pandullo Quirk Associates.

Polk County, 2002. Polk County 2002 Annual Lake and Stream Report . Prepared for the Polk County Board of County Commissioners. Publis hed by the Environmental Services Department, Natural Resources Division, Polk County, Florida. Available at http://www.polk.wateratlas.usf.edu/upload/documents/2002Lk_StrRpt.pdf

. ___, 2005. Polk County Water Atlas Homepage. Available at http://www.polk.wateratlas.usf.edu/

. QEA, LLC, 2005. BATHTUB Model Framework for the Lake Hancock Basin, Polk County, Florida. Prepared for Soil and Water Engineering Technology, In c. Published by Quantitative Environmental Analysis, LLC, Austin, Texas, June, 2005.
Roehl, J. W., 1962. Sediment Source Areas, Delivery Ratios, and Influencing Morphological Factors. International association of Scientific Hydrology. 59: 202-213. Symposium of Bari, October 1-8, 1962.

Shelley, Z. and K. Petrus, 2004. Nutrient Total Maximum Daily Load for Lower Sweetwater Creek, Hillsborough County, Florida . Florida Department of Environmental Protection, Division of Water Resource Management, Watershed Assessment Section, Tallahassee, Florida, September, 2004.

SWET. 1999. EAAMOD Technical and User Manuals . Final Reports to the Everglades Research and Education Center, University of Florida, Belle Glade, Florida.

___, 2002. WAM Training Manual . Developed for EPA Region IV Training. Published by: Soil and Water Engineering Technology, Inc., Gainesville, FL.

___, 2005. Watershed Assessment Model (WAM), Model Documentation and Users/Training Manual. Developed for the Florida Department of Environmental Protection, Division of Water Resource Management, Watershed Assessment Sect ion. Published by Soil and Water Engineering Technology, Inc., Gainesville, Florida, May, 2005.

___, 2005. Watershed Assessment Model (WAM) of the Lake Hancock Basin Final Report. Developed for the Florida Department of Environmental Protection, Division of Water Resource Management, Watershed Assessment Section. Published by Soil and Water Engineering Technology, Inc., Gainesville, Florida, September, 2005.
United States Environmental Protection Agency, April 1991. Guidance for Water Quality – Based Decisions: The TMDL Process. U. S. Environmental Protection Agency, Office of Water, Washington, D.C. EPA-440/4-91-001.

—, November 1999. Protocol for Developing Nutrient TMDLs. U. S. Environmental Protection Agency, Office of Water, Washington, D.C. EPA841-B-99-007.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 82 —, July 2003. 40 CFR 130.2(I), Title 40 – Protection of the Environment, Chapter I – U.S. Environmental Protection Agency, Part 130 – Water Quality Planning and Management, U.S. Environmental Protection Agency, Washington, D.C.
United States Geological Survey, 1981 . Hydrologic Description of Lake Hancock, Polk County, Florida . USGS, WRI 81-131.

—, 2003. Draft Report, Streamflow Losses though Karst Features in the Upper Peace Rive Hydrologic Area, Polk County, Florida, May 2002 – May 2003 . Southwest Florida Water Management District, Brookesville, Florida.

Walker, W. W., 2004. Simplified Procedures for Eutrophication Assessment and Prediction: User Manual, BATHTUB Version 6.1. Instruction Report W-96-2. U. S. Army Corps of Engineers, Waterways Experiment Station, Vi cksburg, Mississippi, April, 2004.

U. S. Census Bureau Web Site. 2004. Available at http://www.census.gov/; or http://factfinder.census.gov/servlet/GCTTable?_bm=y&-geo_id=04000US12&- _box_head_nbr=GCT-PH1&-ds_name=DEC_2000_SF1_U&-_lang=en&-format=ST-2&-_sse=on.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 83 

# Appendices

Appendix A: Background Informati on on Federal and State Stormwater Programs

In 1982, Florida became the first state in the country to implement statewide regulations to address the issue of nonpoint source pollution by r equiring new development and redevelopment to treat stormwater before it is discharged. The Stormwater Rule, as authorized in Chapter 403, F.S., was established as a technology-based program that relies on the implementation of BMPs that are designed to achieve a specific level of treatment (i.e., performance standards) as set forth in Chapter 62-40, F.A.C.

The rule requires the state’s water management districts (WMDs) to establish stormwater pollutant load reduction goals (PLRGs) and adopt them as part of a SWIM plan, other watershed plan, or rule. Stormwater PLRGs are a major component of the load allocation part of a TMDL. To date, stormwater PLRGs have been established for Tampa Bay, Lake Thonotosassa, the Winter Haven Chain of Lakes, the Everglades, Lake Okeechobee, and Lake Apopka. At this time, no PLRG has been developed for Lake Hancock.
In 1987, the U.S. Congress established Section 402(p) as part of the federal Clean Water Act Reauthorization. This section of the law amended the scope of the federal NPDES permitting program to designate certain stormwater discharges as “point sources” of pollution. The EPA promulgated regulations and began implementation of the Phase I NPDES stormwater program in 1990. These stormwater discharges include certain discharges that are associated with industrial activities designated by specific Standard Industr ial Classification (SIC) codes, construction sites disturbing five or more acres of land, and master drainage systems of local governments with a population above 100,000, which are better known as municipal separate storm sewer systems (MS4s). However, because the master drainage systems of most local governments in Florida are interconnected, the EPA implemented Phase I of the MS4 permitting program on a countywide basis, which brought in all cities (incorporated areas), Chapter 298 urban water control districts, and the Florida Department of Transportation throughout the fifteen counties meeting the population criteria. The Department received authorization to implement the NPDES stormwater program in 2000.
An important difference between the NPDES and other state stormwater permitting programs is that the NPDES program covers both new and existing discharges, while the other state programs focus on new discharges. Additionally, Phase II of the NPDES Program, implemented in 2003, expands the need for these permits to construction sites between one and five acres, and to local governments with as few as 1,000 people. While these urban stormwater discharges are now technically referred to as “point sources” for the purpose of regulation, they are still diffuse sources of pollution that cannot be easily collected and treated by a central treatment facility similar to other point sources of pollution, such as domestic and industrial wastewater discharges. It should be noted that all MS4 permits issued in Florida include a re-opener clause that allows permit revisions to implement TMDLs when the impl ementation plan is formally adopted.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 84 Appendix B: TN, TP, Chlorophyll a , and DO Monitoring Data Used in the TMDL Analysis for Lake Hancock and Lower Saddle Creek

Lake Hancock TN Data

WBID Station Date Time Depth Storet Code TN (mg/L) R-Code 1623L 21FLPOLKHANCOCK1 4/ 9/1992 1141 0.50 600 11.22 1623L 21FLPOLKHANCOCK1 10/7/ 1992 1527 0.70 600 4.07 1623L 21FLPOLKHANCOCK1 3/31/ 1993 1530 0.70 600 12.03 1623L 21FLPOLKHANCOCK1 10/7/ 1993 1107 0.70 600 2.04 1623L 21FLPOLKHANCOCK1 12/6/ 1993 1053 0.70 600 4.02 1623L 21FLPOLKHANCOCK1 12/20/ 1993 1043 0.70 600 4.30 1623L 21FLPOLKHANCOCK1 4/12/ 1994 1210 0.60 600 4.87 1623L 21FLPOLKHANCOCK1 10/5/ 1994 1205 0.90 600 1.71 1623L 21FLPOLKHANCOCK1 4/ 5/1995 1230 0.80 600 3.13 1623L 21FLPOLKHANCOCK1 11/8/ 1995 844 0.80 600 2.56 1623L 21FLPOLKHANCOCK1 5/ 8/1996 1200 0.80 600 4.99 1623L 21FLSWFDSTA0192 8/1/1996 1535 0.50 600 4.82 1623L 21FLPOLKHANCOCK1 11/13/ 1996 1248 2.62 600 4.42 1623L 21FLPOLKHANCOCK1 5/ 7/1997 1150 0.10 600 4.63 1623L 21FLPOLKHANCOCK1 10/30/ 1997 1145 0.70 600 1.98 1623L 21FLPOLKHANCOCK1 5/ 7/1998 1245 0.80 600 1.89 1623L 21FLPOLKHANCOCK1 11/9/ 1998 1015 0.60 600 5.15 1623L 21FLPOLKHANCOCK1 5/11/ 1999 900 0.50 600 9.80 1623L 21FLPOLKHANCOCK1 11/9/ 1999 830 0.49 600 5.49 1623L 21FLPOLKHANCOCK1 5/ 3/2000 815 0.30 600 4.11 1623L 21FLPOLKHANCOCK1 11/16/ 2000 1200 0.40 600 5.57 1623L 21FLPOLKHANCOCK1 11/20/ 2001 1400 0.50 600 2.76 1623L 21FLPOLKHANCOCK A 1/ 16/2002 845 0.50 600 4.24 1623L 21FLPOLKHANCOCK B 1/ 16/2002 915 0.50 600 3.00 1623L 21FLPOLKHANCOCK C 1/ 16/2002 945 0.50 600 3.00 1623L 21FLPOLKHANCOCK D 1/ 16/2002 1005 0.50 600 4.19 1623L 21FLPOLKHANCOCK A 2/ 5/2002 1345 0.50 600 5.58 1623L 21FLPOLKHANCOCK B 2/ 5/2002 1410 0.50 600 2.86 1623L 21FLPOLKHANCOCK C 2/ 5/2002 1435 0.50 600 4.15 1623L 21FLPOLKHANCOCK D 2/ 5/2002 1500 0.50 600 5.11 1623L 21FLPOLKHANCOCK A 3/ 7/2002 1355 0.50 600 7.93 1623L 21FLPOLKHANCOCK B 3/ 7/2002 1400 0.50 600 4.54 1623L 21FLPOLKHANCOCK C 3/ 7/2002 1416 0.50 600 4.60 1623L 21FLPOLKHANCOCK D 3/ 7/2002 1430 0.50 600 8.06 1623L 21FLPOLKHANCOCK H-10 8/ 22/2002 810 0.50 600 2.03 1623L 21FLPOLKHANCOCK H-16 8/ 22/2002 840 0.50 600 4.06 1623L 21FLPOLKHANCOCK H-17 8/ 22/2002 820 0.50 600 4.46 1623L 21FLPOLKHANCOCK H-18 8/ 22/2002 830 0.50 600 4.78 1623L 21FLPOLKHANCOCK H-2 8/ 22/2002 805 0.50 600 1.69 1623L 21FLPOLKHANCOCK H-23 8/ 22/2002 845 0.50 600 2.88 1623L 21FLPOLKHANCOCK H-26 8/ 22/2002 920 0.50 600 3.99DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 85 WBID Station Date Time Depth Storet Code TN (mg/L) R-Code 1623L 21FLPOLKHANCOCK H-37 8/ 22/2002 855 0.50 600 4.92 1623L 21FLPOLKHANCOCK H-4 8/ 22/2002 750 0.50 600 1.48 1623L 21FLPOLKHANCOCK H-52 8/ 22/2002 930 0.50 600 4.94 1623L 21FLPOLKHANCOCK H-59 8/ 22/2002 945 0.50 600 4.47 1623L 21FLPOLKHANCOCK H-62 8/ 22/2002 1000 0.50 600 4.41 1623L 21FLPOLKHANCOCK H-12 11/ 18/2002 1305 0.50 600 2.43 1623L 21FLPOLKHANCOCK H-16 11/ 18/2002 945 0.20 600 3.25 1623L 21FLPOLKHANCOCK H-19 11/ 18/2002 1255 0.50 600 2.55 1623L 21FLPOLKHANCOCK H-2 11/ 18/2002 925 0.40 600 1.19 1623L 21FLPOLKHANCOCK H-23 11/ 18/2002 1005 0.50 600 3.90 1623L 21FLPOLKHANCOCK H-25 11/ 18/2002 1240 0.40 600 3.44 1623L 21FLPOLKHANCOCK H-30 11/ 18/2002 1020 0.50 600 4.57 1623L 21FLPOLKHANCOCK H-33 11/ 18/2002 1150 0.50 600 3.26 1623L 21FLPOLKHANCOCK H-36 11/ 18/2002 1035 0.40 600 4.81 1623L 21FLPOLKHANCOCK H-40 11/ 18/2002 1130 0.40 600 1.83 1623L 21FLPOLKHANCOCK H-53 11/ 18/2002 1225 0.50 600 4.01 1623L 21FLPOLKHANCOCK H-55 11/ 18/2002 1210 0.40 600 3.99 1623L 21FLTPA 25020276 2/4/2003 940 0.20 600 1.51 + 1623L 21FLPOLKHANCOCK H-16 2/ 13/2003 825 0.50 600 2.73 1623L 21FLPOLKHANCOCK H-17 2/ 13/2003 840 0.50 600 3.38 1623L 21FLPOLKHANCOCK H-22 2/ 13/2003 915 0.45 600 3.38 1623L 21FLPOLKHANCOCK H-25 2/ 13/2003 900 0.50 600 3.48 1623L 21FLPOLKHANCOCK H-29 2/ 13/2003 920 0.50 600 3.82 1623L 21FLPOLKHANCOCK H-30 2/ 13/2003 945 0.50 600 3.64 1623L 21FLPOLKHANCOCK H-36 2/ 13/2003 935 0.45 600 3.83 1623L 21FLPOLKHANCOCK H-41 2/ 13/2003 1040 0.50 600 2.13 1623L 21FLPOLKHANCOCK H-45 2/ 13/2003 1110 0.50 600 3.39 1623L 21FLPOLKHANCOCK H-47 2/ 13/2003 1055 0.50 600 2.26 1623L 21FLPOLKHANCOCK H-59 2/ 13/2003 1120 0.50 600 3.05 1623L 21FLPOLKHANCOCK H-62 2/ 13/2003 1140 0.50 600 2.95 1623L 21FLTPA 25020276 4/22/2003 1110 0.20 600 4.00 + 1623L 21FLPOLKHANCOCK H-24 5/ 20/2003 1150 0.50 600 7.04 1623L 21FLPOLKHANCOCK H-25 5/ 20/2003 1140 0.50 600 6.56 1623L 21FLPOLKHANCOCK H-31 5/ 20/2003 1200 0.50 600 7.38 1623L 21FLPOLKHANCOCK H-32 5/ 20/2003 1210 0.50 600 5.45 1623L 21FLPOLKHANCOCK H-37 5/ 20/2003 1010 0.50 600 7.20 1623L 21FLPOLKHANCOCK H-38 5/ 20/2003 1000 0.50 600 6.30 1623L 21FLPOLKHANCOCK H-4 5/ 20/2003 1115 0.50 600 2.31 1623L 21FLPOLKHANCOCK H-40 5/ 20/2003 845 0.50 600 7.27 1623L 21FLPOLKHANCOCK H-47 5/ 20/2003 900 0.50 600 5.72 1623L 21FLPOLKHANCOCK H-52 5/ 20/2003 950 0.50 600 7.28 1623L 21FLPOLKHANCOCK H-53 5/ 20/2003 940 0.50 600 6.83 1623L 21FLPOLKHANCOCK H-56 5/ 20/2003 920 0.40 600 4.81 1623L 21FLTPA 25020276 8/18/2003 900 0.20 600 2.60 + 1623L 21FLPOLKHANCOCK H-18 8/ 20/2003 840 0.50 600 4.19 1623L 21FLPOLKHANCOCK H-23 8/ 20/2003 855 0.50 600 3.01 1623L 21FLPOLKHANCOCK H-24 8/ 20/2003 850 0.50 600 5.26DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 86 WBID Station Date Time Depth Storet Code TN (mg/L) R-Code 1623L 21FLPOLKHANCOCK H-37 8/ 20/2003 910 0.50 600 3.69 1623L 21FLPOLKHANCOCK H-38 8/ 20/2003 920 0.50 600 3.34 1623L 21FLPOLKHANCOCK H-39 8/ 20/2003 930 0.50 600 5.54 1623L 21FLPOLKHANCOCK H-4 8/ 20/2003 820 0.50 600 1.37 1623L 21FLPOLKHANCOCK H-47 8/ 20/2003 1050 0.50 600 4.09 1623L 21FLPOLKHANCOCK H-48 8/ 20/2003 1040 0.50 600 3.09 1623L 21FLPOLKHANCOCK H-51 8/ 20/2003 1000 0.50 600 3.26 1623L 21FLPOLKHANCOCK H-59 8/ 20/2003 1015 0.50 600 3.42 1623L 21FLPOLKHANCOCK H-61 8/ 20/2003 1025 0.50 600 4.72 1623L 21FLTPA 25020276 11/3/2003 1040 0.20 600 3.30 + 1623L 21FLPOLKHANCOCK H-11 11/ 18/2003 1150 0.50 600 4.13 1623L 21FLPOLKHANCOCK H-16 11/ 18/2003 1130 0.50 600 5.76 1623L 21FLPOLKHANCOCK H-22 11/ 18/2003 1120 0.50 600 4.42 1623L 21FLPOLKHANCOCK H-3 11/ 18/2003 1140 0.50 600 4.87 1623L 21FLPOLKHANCOCK H-30 11/ 18/2003 1110 0.50 600 4.79 1623L 21FLPOLKHANCOCK H-31 11/ 18/2003 1100 0.50 600 4.89 1623L 21FLPOLKHANCOCK H-34 11/ 18/2003 945 0.50 600 4.26 1623L 21FLPOLKHANCOCK H-40 11/ 18/2003 955 0.50 600 5.13 1623L 21FLPOLKHANCOCK H-43 11/ 18/2003 1010 0.50 600 5.07 1623L 21FLPOLKHANCOCK H-48 11/ 18/2003 905 0.50 600 5.13 1623L 21FLPOLKHANCOCK H-49 11/ 18/2003 920 0.50 600 3.09 1623L 21FLPOLKHANCOCK H-54 11/ 18/2003 850 0.50 600 4.01 1623L 21FLPOLKHANCOCK H-11 2/19/2004 1120 0.50 600 4.06 + 1623L 21FLPOLKHANCOCK H-22 2/19/2004 1055 0.50 600 4.70 + 1623L 21FLPOLKHANCOCK H-24 2/19/2004 1110 0.50 600 3.64 + 1623L 21FLPOLKHANCOCK H-30 2/19/2004 1045 0.50 600 4.86 + 1623L 21FLPOLKHANCOCK H-33 2/19/2004 950 0.50 600 4.89 + 1623L 21FLPOLKHANCOCK H-34 2/19/2004 1000 0.50 600 4.70 + 1623L 21FLPOLKHANCOCK H-36 2/19/2004 920 0.50 600 5.13 + 1623L 21FLPOLKHANCOCK H-37 2/19/2004 935 0.50 600 4.39 + 1623L 21FLPOLKHANCOCK H-44 2/19/2004 905 0.50 600 5.01 + 1623L 21FLPOLKHANCOCK H-59 2/19/2004 850 0.50 600 3.95 + 1623L 21FLPOLKHANCOCK H-62 2/19/2004 830 0.50 600 4.65 + 1623L 21FLPOLKHANCOCK H-9 2/19/2004 1130 0.50 600 4.91 + 1623L 21FLPOLKHANCOCK H-12 5/5/2004 950 0.50 600 4.79 + 1623L 21FLPOLKHANCOCK H-22 5/5/2004 925 0.40 600 8.53 + 1623L 21FLPOLKHANCOCK H-3 5/5/2004 940 0.40 600 7.30 + 1623L 21FLPOLKHANCOCK H-31 5/5/2004 835 0.50 600 8.40 + 1623L 21FLPOLKHANCOCK H-33 5/5/2004 825 0.50 600 6.15 + 1623L 21FLPOLKHANCOCK H-36 5/5/2004 915 0.50 600 8.64 + 1623L 21FLPOLKHANCOCK H-40 5/5/2004 815 0.50 600 7.06 + 1623L 21FLPOLKHANCOCK H-43 5/5/2004 910 0.50 600 8.40 + 1623L 21FLPOLKHANCOCK H-47 5/5/2004 805 0.50 600 8.11 + 1623L 21FLPOLKHANCOCK H-50 5/5/2004 900 0.50 600 4.98 + 1623L 21FLPOLKHANCOCK H-54 5/5/2004 755 0.50 600 7.85 + 1623L 21FLPOLKHANCOCK H-62 5/5/2004 745 0.50 600 7.20 + + : Calculated value.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 87 Lake Hancock TP Data

WBID Station Date Time Depth Storet Code TP (mg/L) R-Code 1623L 21FLPOLKHANCOCK1 4/ 9/1992 1141 0.50 665 0.94 1623L 21FLPOLKHANCOCK1 10/7/ 1992 1527 0.70 665 0.37 1623L 21FLPOLKHANCOCK1 3/31/ 1993 1530 0.70 665 0.71 1623L 21FLPOLKHANCOCK1 10/7/ 1993 1107 0.70 665 0.20 1623L 21FLPOLKHANCOCK1 12/6/ 1993 1053 0.70 665 0.17 1623L 21FLPOLKHANCOCK1 12/20/ 1993 1043 0.70 665 0.20 1623L 21FLPOLKHANCOCK1 4/12/ 1994 1210 0.60 665 0.47 1623L 21FLPOLKHANCOCK1 10/5/ 1994 1205 0.90 665 0.36 1623L 21FLPOLKHANCOCK1 4/ 5/1995 1230 0.80 665 0.42 1623L 21FLPOLKHANCOCK1 11/8/ 1995 844 0.80 665 0.49 1623L 21FLPOLKHANCOCK1 5/ 8/1996 1200 0.80 665 0.51 1623L 21FLSWFDSTA0192 8/1/1996 1535 0.50 665 0.04 1623L 21FLPOLKHANCOCK1 11/13/ 1996 1248 2.62 665 0.42 1623L 21FLPOLKHANCOCK1 5/ 7/1997 1150 0.10 665 0.43 1623L 21FLPOLKHANCOCK1 10/30/ 1997 1145 0.70 665 0.11 1623L 21FLPOLKHANCOCK1 5/ 7/1998 1245 0.80 665 0.54 1623L 21FLPOLKHANCOCK1 11/9/ 1998 1015 0.60 665 0.49 1623L 21FLPOLKHANCOCK1 5/11/ 1999 900 0.50 665 0.75 1623L 21FLPOLKHANCOCK1 11/9/ 1999 830 0.49 665 0.53 1623L 21FLPOLKHANCOCK1 5/ 3/2000 815 0.30 665 0.36 1623L 21FLPOLKHANCOCK1 11/16/ 2000 1200 0.40 665 0.23 1623L 21FLPOLKHANCOCK1 11/20/ 2001 1400 0.50 665 0.77 1623L 21FLPOLKHANCOCK A 1/ 16/2002 845 0.50 665 0.76 1623L 21FLPOLKHANCOCK B 1/ 16/2002 915 0.50 665 0.97 1623L 21FLPOLKHANCOCK C 1/ 16/2002 945 0.50 665 0.73 1623L 21FLPOLKHANCOCK D 1/ 16/2002 1005 0.50 665 0.74 1623L 21FLPOLKHANCOCK A 2/ 5/2002 1345 0.50 665 0.81 1623L 21FLPOLKHANCOCK B 2/ 5/2002 1410 0.50 665 1.01 1623L 21FLPOLKHANCOCK C 2/ 5/2002 1435 0.50 665 0.73 1623L 21FLPOLKHANCOCK D 2/ 5/2002 1500 0.50 665 0.76 1623L 21FLPOLKHANCOCK A 3/ 7/2002 1355 0.50 665 0.82 1623L 21FLPOLKHANCOCK B 3/ 7/2002 1400 0.50 665 0.80 1623L 21FLPOLKHANCOCK C 3/ 7/2002 1416 0.50 665 0.71 1623L 21FLPOLKHANCOCK D 3/ 7/2002 1430 0.50 665 0.82 1623L 21FLPOLKHANCOCK H-10 8/ 22/2002 810 0.50 665 0.44 1623L 21FLPOLKHANCOCK H-16 8/ 22/2002 840 0.50 665 0.39 1623L 21FLPOLKHANCOCK H-17 8/ 22/2002 820 0.50 665 0.34 1623L 21FLPOLKHANCOCK H-18 8/ 22/2002 830 0.50 665 0.42 1623L 21FLPOLKHANCOCK H-2 8/ 22/2002 805 0.50 665 0.50 1623L 21FLPOLKHANCOCK H-23 8/ 22/2002 845 0.50 665 0.38 1623L 21FLPOLKHANCOCK H-26 8/ 22/2002 920 0.50 665 0.34 1623L 21FLPOLKHANCOCK H-37 8/ 22/2002 855 0.50 665 0.39 1623L 21FLPOLKHANCOCK H-4 8/ 22/2002 750 0.50 665 0.54 1623L 21FLPOLKHANCOCK H-52 8/ 22/2002 930 0.50 665 0.37 1623L 21FLPOLKHANCOCK H-59 8/22/2002 945 0.50 665 0.30 ADRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 88 WBID Station Date Time Depth Storet Code TP (mg/L) R-Code 1623L 21FLPOLKHANCOCK H-62 8/ 22/2002 1000 0.50 665 0.33 1623L 21FLPOLKHANCOCK H-12 11/ 18/2002 1305 0.50 665 0.34 1623L 21FLPOLKHANCOCK H-16 11/ 18/2002 945 0.20 665 0.43 1623L 21FLPOLKHANCOCK H-19 11/ 18/2002 1255 0.50 665 0.42 1623L 21FLPOLKHANCOCK H-2 11/ 18/2002 925 0.40 665 0.45 1623L 21FLPOLKHANCOCK H-23 11/ 18/2002 1005 0.50 665 0.41 1623L 21FLPOLKHANCOCK H-25 11/ 18/2002 1240 0.40 665 0.43 1623L 21FLPOLKHANCOCK H-30 11/ 18/2002 1020 0.50 665 0.48 1623L 21FLPOLKHANCOCK H-33 11/ 18/2002 1150 0.50 665 0.37 1623L 21FLPOLKHANCOCK H-36 11/ 18/2002 1035 0.40 665 0.49 1623L 21FLPOLKHANCOCK H-40 11/ 18/2002 1130 0.40 665 0.10 1623L 21FLPOLKHANCOCK H-53 11/ 18/2002 1225 0.50 665 0.41 1623L 21FLPOLKHANCOCK H-55 11/ 18/2002 1210 0.40 665 0.35 1623L 21FLTPA 25020276 2/4/2003 940 0.20 665 0.43 1623L 21FLPOLKHANCOCK H-16 2/ 13/2003 825 0.50 665 0.56 1623L 21FLPOLKHANCOCK H-17 2/ 13/2003 840 0.50 665 0.56 1623L 21FLPOLKHANCOCK H-22 2/ 13/2003 915 0.45 665 0.59 1623L 21FLPOLKHANCOCK H-25 2/ 13/2003 900 0.50 665 0.55 1623L 21FLPOLKHANCOCK H-29 2/ 13/2003 920 0.50 665 0.62 1623L 21FLPOLKHANCOCK H-30 2/ 13/2003 945 0.50 665 0.59 1623L 21FLPOLKHANCOCK H-36 2/ 13/2003 935 0.45 665 0.63 1623L 21FLPOLKHANCOCK H-41 2/ 13/2003 1040 0.50 665 0.42 1623L 21FLPOLKHANCOCK H-45 2/ 13/2003 1110 0.50 665 0.58 1623L 21FLPOLKHANCOCK H-47 2/ 13/2003 1055 0.50 665 0.46 1623L 21FLPOLKHANCOCK H-59 2/ 13/2003 1120 0.50 665 0.57 1623L 21FLPOLKHANCOCK H-62 2/ 13/2003 1140 0.50 665 0.54 1623L 21FLTPA 25020276 4/22/2003 1110 0.20 665 0.68 1623L 21FLPOLKHANCOCK H-24 5/ 20/2003 1150 0.50 665 0.95 1623L 21FLPOLKHANCOCK H-25 5/ 20/2003 1140 0.50 665 0.83 1623L 21FLPOLKHANCOCK H-31 5/ 20/2003 1200 0.50 665 0.95 1623L 21FLPOLKHANCOCK H-32 5/ 20/2003 1210 0.50 665 0.89 1623L 21FLPOLKHANCOCK H-37 5/ 20/2003 1010 0.50 665 0.88 1623L 21FLPOLKHANCOCK H-37 5/ 20/2003 1015 0.50 665 0.89 1623L 21FLPOLKHANCOCK H-38 5/ 20/2003 1000 0.50 665 0.87 1623L 21FLPOLKHANCOCK H-4 5/ 20/2003 1115 0.50 665 0.52 1623L 21FLPOLKHANCOCK H-40 5/ 20/2003 845 0.50 665 0.94 1623L 21FLPOLKHANCOCK H-47 5/ 20/2003 900 0.50 665 0.67 1623L 21FLPOLKHANCOCK H-52 5/ 20/2003 950 0.50 665 0.91 1623L 21FLPOLKHANCOCK H-53 5/ 20/2003 940 0.50 665 0.85 1623L 21FLPOLKHANCOCK H-56 5/ 20/2003 920 0.40 665 0.66 1623L 21FLTPA 25020276 8/18/2003 900 0.20 665 0.35 1623L 21FLPOLKHANCOCK H-18 8/ 20/2003 840 0.50 665 0.41 1623L 21FLPOLKHANCOCK H-23 8/ 20/2003 855 0.50 665 0.49 1623L 21FLPOLKHANCOCK H-24 8/ 20/2003 850 0.50 665 0.54 1623L 21FLPOLKHANCOCK H-37 8/ 20/2003 910 0.50 665 0.41 1623L 21FLPOLKHANCOCK H-38 8/ 20/2003 920 0.50 665 0.40 1623L 21FLPOLKHANCOCK H-39 8/ 20/2003 930 0.50 665 0.55DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 89 WBID Station Date Time Depth Storet Code TP (mg/L) R-Code 1623L 21FLPOLKHANCOCK H-4 8/ 20/2003 820 0.50 665 0.40 1623L 21FLPOLKHANCOCK H-47 8/ 20/2003 1050 0.50 665 0.38 1623L 21FLPOLKHANCOCK H-48 8/ 20/2003 1040 0.50 665 0.33 1623L 21FLPOLKHANCOCK H-51 8/ 20/2003 1000 0.50 665 0.36 1623L 21FLPOLKHANCOCK H-59 8/ 20/2003 1015 0.50 665 0.37 1623L 21FLPOLKHANCOCK H-61 8/ 20/2003 1025 0.50 665 0.49 1623L 21FLTPA 25020276 11/3/2003 1040 0.20 665 0.50 1623L 21FLPOLKHANCOCK H-11 11/ 18/2003 1150 0.50 665 0.46 1623L 21FLPOLKHANCOCK H-16 11/ 18/2003 1130 0.50 665 0.58 1623L 21FLPOLKHANCOCK H-22 11/ 18/2003 1120 0.50 665 0.52 1623L 21FLPOLKHANCOCK H-3 11/ 18/2003 1140 0.50 665 0.50 1623L 21FLPOLKHANCOCK H-30 11/ 18/2003 1110 0.50 665 0.41 1623L 21FLPOLKHANCOCK H-31 11/ 18/2003 1100 0.50 665 0.46 1623L 21FLPOLKHANCOCK H-34 11/ 18/2003 945 0.50 665 0.42 1623L 21FLPOLKHANCOCK H-40 11/ 18/2003 955 0.50 665 0.53 1623L 21FLPOLKHANCOCK H-43 11/ 18/2003 1010 0.50 665 0.45 1623L 21FLPOLKHANCOCK H-48 11/ 18/2003 905 0.50 665 0.52 1623L 21FLPOLKHANCOCK H-49 11/ 18/2003 920 0.50 665 0.40 1623L 21FLPOLKHANCOCK H-54 11/ 18/2003 850 0.50 665 0.40 1623L 21FLPOLKHANCOCK H-11 2/ 19/2004 1120 0.50 665 0.27 1623L 21FLPOLKHANCOCK H-22 2/ 19/2004 1055 0.50 665 0.36 1623L 21FLPOLKHANCOCK H-24 2/ 19/2004 1110 0.50 665 0.27 1623L 21FLPOLKHANCOCK H-30 2/ 19/2004 1045 0.50 665 0.41 1623L 21FLPOLKHANCOCK H-33 2/ 19/2004 950 0.50 665 0.33 1623L 21FLPOLKHANCOCK H-34 2/ 19/2004 1000 0.50 665 0.36 1623L 21FLPOLKHANCOCK H-36 2/ 19/2004 920 0.50 665 0.43 1623L 21FLPOLKHANCOCK H-37 2/ 19/2004 935 0.50 665 0.35 1623L 21FLPOLKHANCOCK H-44 2/ 19/2004 905 0.50 665 0.37 1623L 21FLPOLKHANCOCK H-59 2/ 19/2004 850 0.50 665 0.40 1623L 21FLPOLKHANCOCK H-62 2/ 19/2004 830 0.50 665 0.34 1623L 21FLPOLKHANCOCK H-9 2/ 19/2004 1130 0.50 665 0.39 1623L 21FLPOLKHANCOCK H-12 5/5/2004 950 0.50 665 0.36 1623L 21FLPOLKHANCOCK H-22 5/5/2004 925 0.40 665 0.64 1623L 21FLPOLKHANCOCK H-3 5/5/2004 940 0.40 665 0.62 1623L 21FLPOLKHANCOCK H-31 5/5/2004 835 0.50 665 0.55 1623L 21FLPOLKHANCOCK H-33 5/5/2004 825 0.50 665 0.60 1623L 21FLPOLKHANCOCK H-36 5/5/2004 915 0.50 665 0.57 1623L 21FLPOLKHANCOCK H-40 5/5/2004 815 0.50 665 0.61 1623L 21FLPOLKHANCOCK H-43 5/5/2004 910 0.50 665 0.61 1623L 21FLPOLKHANCOCK H-47 5/5/2004 805 0.50 665 0.65 1623L 21FLPOLKHANCOCK H-50 5/5/2004 900 0.50 665 0.55 1623L 21FLPOLKHANCOCK H-54 5/5/2004 755 0.50 665 0.51 1623L 21FLPOLKHANCOCK H-62 5/5/2004 745 0.50 665 0.56 A: Value reported is the mean of two or more determinations.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 90 Lake Hancock Chlorophyll a Data

WBID Station Date Time Depth Storet Code Chla ( μ g/L) R-Code 1623L 21FLPOLKHANCOCK1 4/9/ 1992 1141 1.64 32210 310.5 1623L 21FLPOLKHANCOCK1 10/7/ 1992 1527 4.59 32210 131.8 1623L 21FLPOLKHANCOCK1 3/31/ 1993 1530 2.30 32210 173.1 1623L 21FLPOLKHANCOCK1 10/7/ 1993 1107 2.30 32210 66.4 1623L 21FLPOLKHANCOCK1 12/6/ 1993 1053 2.30 32210 87.8 1623L 21FLPOLKHANCOCK1 12/20/ 1993 1043 2.30 32210 67.3 1623L 21FLPOLKHANCOCK1 4/12/ 1994 1210 1.97 32210 204.5 1623L 21FLPOLKHANCOCK1 10/5/ 1994 1205 2.95 32210 78.8 1623L 21FLPOLKHANCOCK1 4/5/ 1995 1230 2.62 32210 158.9 1623L 21FLPOLKHANCOCK1 11/8/ 1995 844 2.62 32210 161.8 1623L 21FLPOLKHANCOCK1 5/8/ 1996 1200 2.62 32210 186.6 1623L 21FLSWFDSTA0192 8/1/1996 1535 0.50 32210 24.1 1623L 21FLSWFDSTA0192 8/1/1996 1535 0.50 32211 23.3 1623L 21FLPOLKHANCOCK1 11/13/ 1996 1248 2.62 32210 130.1 1623L 21FLSWFDSTA0192 1/13/1997 2500 0.50 32210 171.3 1623L 21FLSWFDSTA0192 1/13/1997 2500 0.50 32211 137.8 1623L 21FLPOLKHANCOCK1 5/7/ 1997 1150 0.33 32210 152.0 1623L 21FLPOLKHANCOCK1 10/30/ 1997 1145 2.30 32210 71.5 1623L 21FLPOLKHANCOCK1 5/7/ 1998 1245 0.80 32210 86.5 1623L 21FLPOLKHANCOCK1 11/9/ 1998 1015 1.97 32210 237.9 1623L 21FLPOLKHANCOCK1 5/11/ 1999 900 0.50 32223 216.3 1623L 21FLPOLKHANCOCK1 11/9/ 1999 830 0.49 32223 104.1 1623L 21FLPOLKHANCOCK1 5/3/ 2000 815 0.30 32223 144.2 1623L 21FLPOLKHANCOCK1 11/16/ 2000 1200 0.40 32223 116.2 1623L 21FLPOLKHANCOCK1 11/20/ 2001 1400 0.50 32223 65.7 1623L 21FLPOLKHANCOCK A 1/ 16/2002 845 0.50 32223 152.2 E 1623L 21FLPOLKHANCOCK B 1/ 16/2002 915 0.50 32223 34.4 E 1623L 21FLPOLKHANCOCK C 1/ 16/2002 945 0.50 32223 76.9 E 1623L 21FLPOLKHANCOCK D 1/16/ 2002 1005 0.50 32223 146.9 1623L 21FLPOLKHANCOCK A 2/ 5/2002 1345 0.50 32223 175.2 E 1623L 21FLPOLKHANCOCK B 2/ 5/2002 1410 0.50 32223 53.7 E 1623L 21FLPOLKHANCOCK C 2/ 5/2002 1435 0.50 32223 106.1 E 1623L 21FLPOLKHANCOCK D 2/ 5/2002 1500 0.50 32223 184.2 E 1623L 21FLPOLKHANCOCK A 3/ 7/2002 1355 0.50 32223 483.0 1623L 21FLPOLKHANCOCK B 3/ 7/2002 1400 0.50 32223 166.0 1623L 21FLPOLKHANCOCK C 3/ 7/2002 1416 0.50 32223 348.0 1623L 21FLPOLKHANCOCK D 3/ 7/2002 1430 0.50 32223 558.0 1623L 21FLPOLKHANCOCK H-10 8/ 22/2002 810 0.50 32223 43.3 1623L 21FLPOLKHANCOCK H-16 8/ 22/2002 840 0.50 32223 128.2 1623L 21FLPOLKHANCOCK H-17 8/ 22/2002 820 0.50 32223 172.2 1623L 21FLPOLKHANCOCK H-18 8/ 22/2002 830 0.50 32223 164.2 1623L 21FLPOLKHANCOCK H-2 8/ 22/2002 805 0.50 32223 17.6 1623L 21FLPOLKHANCOCK H-23 8/ 22/2002 845 0.50 32223 88.1 1623L 21FLPOLKHANCOCK H-26 8/ 22/2002 920 0.50 32223 128.2 1623L 21FLPOLKHANCOCK H-37 8/ 22/2002 855 0.50 32223 144.2DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 91 WBID Station Date Time Depth Storet Code Chla ( μ g/L) R-Code 1623L 21FLPOLKHANCOCK H-4 8/ 22/2002 750 0.50 32223 16.0 1623L 21FLPOLKHANCOCK H-52 8/ 22/2002 930 0.50 32223 134.2 1623L 21FLPOLKHANCOCK H-59 8/ 22/2002 945 0.50 32223 144.2 1623L 21FLPOLKHANCOCK H-62 8/ 22/2002 1000 0.50 32223 136.8 A 1623L 21FLTPA 25020276 2/4/2003 940 0.20 32209 57.0 Q 1623L 21FLTPA 25020276 4/22/2003 1110 0.20 32209 230.0 1623L 21FLTPA 25020276 8/18/2003 900 0.20 32209 85.0 1623L 21FLTPA 25020276 11/3/2003 1040 0.20 32209 210.0 1623L 21FLPOLKHANCOCK H-11 2/ 19/2004 1120 0.50 32210 146.4 1623L 21FLPOLKHANCOCK H-22 2/ 19/2004 1055 0.50 32210 143.7 1623L 21FLPOLKHANCOCK H-24 2/ 19/2004 1110 0.50 32210 137.8 1623L 21FLPOLKHANCOCK H-30 2/ 19/2004 1045 0.50 32210 156.6 1623L 21FLPOLKHANCOCK H-33 2/ 19/2004 950 0.50 32210 175.5 1623L 21FLPOLKHANCOCK H-34 2/ 19/2004 1000 0.50 32210 143.1 1623L 21FLPOLKHANCOCK H-36 2/ 19/2004 920 0.50 32210 148.0 1623L 21FLPOLKHANCOCK H-37 2/ 19/2004 935 0.50 32210 168.6 1623L 21FLPOLKHANCOCK H-44 2/ 19/2004 905 0.50 32210 148.0 1623L 21FLPOLKHANCOCK H-59 2/ 19/2004 850 0.50 32210 170.1 1623L 21FLPOLKHANCOCK H-62 2/ 19/2004 830 0.50 32210 134.3 1623L 21FLPOLKHANCOCK H-9 2/ 19/2004 1130 0.50 32210 213.7 1623L 21FLPOLKHANCOCK H-12 5/ 5/2004 950 0.50 32210 171.5 1623L 21FLPOLKHANCOCK H-22 5/ 5/2004 925 0.40 32210 364.5 1623L 21FLPOLKHANCOCK H-3 5/ 5/2004 940 0.40 32210 349.7 1623L 21FLPOLKHANCOCK H-31 5/ 5/2004 835 0.50 32210 343.4 1623L 21FLPOLKHANCOCK H-33 5/ 5/2004 825 0.50 32210 289.8 1623L 21FLPOLKHANCOCK H-36 5/ 5/2004 915 0.50 32210 360.7 1623L 21FLPOLKHANCOCK H-40 5/ 5/2004 815 0.50 32210 333.7 1623L 21FLPOLKHANCOCK H-43 5/ 5/2004 910 0.50 32210 346.9 1623L 21FLPOLKHANCOCK H-47 5/ 5/2004 805 0.50 32210 346.2 1623L 21FLPOLKHANCOCK H-50 5/ 5/2004 900 0.50 32210 362.3 1623L 21FLPOLKHANCOCK H-54 5/ 5/2004 755 0.50 32210 312.8 1623L 21FLPOLKHANCOCK H-62 5/ 5/2004 745 0.50 32210 327.3

A: Value reported is the mean of two or more determinations. E: Extra sample taken in compositing process. Q: Sample held beyond normal holding time.DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 92 Lake Hancock Dissolved Oxygen Data

WBID Station Date Time Depth Storet Code DO (mg/L) R-Code 1623L 21FLPOLKHANCOCK1 4/ 9/1992 1141 0.50 299 10.60 1623L 21FLPOLKHANCOCK1 10/7/ 1992 1527 0.70 299 2.50 1623L 21FLPOLKHANCOCK1 3/31/ 1993 1530 0.70 299 0.90 1623L 21FLPOLKHANCOCK1 10/7/ 1993 1107 0.70 299 7.10 1623L 21FLPOLKHANCOCK1 12/6/ 1993 1053 0.70 299 11.70 1623L 21FLPOLKHANCOCK1 12/20/ 1993 1043 0.70 299 12.50 1623L 21FLPOLKHANCOCK1 4/12/ 1994 1210 0.60 299 9.30 1623L 21FLPOLKHANCOCK1 10/5/ 1994 1205 0.90 299 8.60 1623L 21FLPOLKHANCOCK1 4/ 5/1995 1230 0.80 299 11.50 1623L 21FLPOLKHANCOCK1 11/8/ 1995 844 0.80 299 7.30 1623L 21FLPOLKHANCOCK1 5/ 8/1996 1200 0.80 299 7.90 1623L 21FLSWFDSTA0192 8/1/1996 1535 0.50 299 6.10 1623L 21FLPOLKHANCOCK1 11/13/ 1996 1248 0.80 299 11.30 1623L 21FLSWFDSTA0192 1/13/1997 1500 0.50 299 12.23 1623L 21FLPOLKHANCOCK1 5/ 7/1997 1150 0.10 299 15.70 1623L 21FLPOLKHANCOCK1 10/30/ 1997 1145 0.70 299 10.95 1623L 21FLPOLKHANCOCK1 5/ 7/1998 1245 0.80 299 11.56 1623L 21FLPOLKHANCOCK1 11/9/ 1998 1015 0.60 299 11.92 1623L 21FLPOLKHANCOCK1 5/11/ 1999 900 0.50 299 4.39 1623L 21FLTPA 25020275 9/7/1999 1110 0.30 299 7.98 1623L 21FLTPA 25020276 9/7/1999 145 0.30 299 9.25 1623L 21FLTPA 25020278 9/8/1999 1115 0.60 299 7.98 1623L 21FLTPA 25020277 9/8/1999 140 0.60 299 10.30 1623L 21FLPOLKHANCOCK1 11/9/ 1999 830 0.49 299 9.05 1623L 21FLPOLKHANCOCK1 5/ 3/2000 815 0.30 299 0.84 1623L 21FLPOLKHANCOCK1 11/16/ 2000 1200 0.40 299 10.08 1623L 21FLPOLKHANCOCK1 11/20/ 2001 1400 0.50 299 12.95 1623L 21FLPOLKHANCOCK B 1/ 16/2002 915 0.50 299 2.21 1623L 21FLPOLKHANCOCK C 1/ 16/2002 945 0.50 299 7.56 1623L 21FLPOLKHANCOCK A 1/ 16/2002 845 0.50 299 11.32 1623L 21FLPOLKHANCOCK D 1/ 16/2002 1005 0.50 299 12.57 1623L 21FLPOLKHANCOCK B 2/ 5/2002 1410 0.50 299 7.29 1623L 21FLPOLKHANCOCK C 2/ 5/2002 1435 0.50 299 12.60 1623L 21FLPOLKHANCOCK A 2/ 5/2002 1345 0.50 299 13.17 1623L 21FLPOLKHANCOCK D 2/ 5/2002 1500 0.50 299 14.45 1623L 21FLPOLKHANCOCK B 3/ 7/2002 1400 0.50 299 1.51 1623L 21FLPOLKHANCOCK D 3/ 7/2002 1430 0.50 299 1.52 1623L 21FLPOLKHANCOCK A 3/ 7/2002 1355 0.50 299 4.79 1623L 21FLPOLKHANCOCK C 3/ 7/2002 1416 0.50 299 11.77 1623L 21FLPOLKHANCOCK H-4 8/ 22/2002 750 0.50 299 0.38 1623L 21FLPOLKHANCOCK H-2 8/ 22/2002 805 0.50 299 3.08 1623L 21FLPOLKHANCOCK H-23 8/ 22/2002 845 0.50 299 4.36 1623L 21FLPOLKHANCOCK H-10 8/ 22/2002 810 0.50 299 4.43 1623L 21FLPOLKHANCOCK H-62 8/ 22/2002 1000 0.50 299 4.94 1623L 21FLPOLKHANCOCK H-52 8/ 22/2002 930 0.50 299 5.42DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 93 WBID Station Date Time Depth Storet Code DO (mg/L) R-Code 1623L 21FLPOLKHANCOCK H-52 8/ 22/2002 935 0.50 299 5.42 1623L 21FLPOLKHANCOCK H-37 8/ 22/2002 855 0.50 299 6.19 1623L 21FLPOLKHANCOCK H-16 8/ 22/2002 840 0.50 299 6.51 1623L 21FLPOLKHANCOCK H-17 8/ 22/2002 820 0.50 299 7.47 1623L 21FLPOLKHANCOCK H-59 8/ 22/2002 945 0.50 299 7.86 1623L 21FLPOLKHANCOCK H-18 8/ 22/2002 830 0.50 299 8.14 1623L 21FLPOLKHANCOCK H-26 8/ 22/2002 920 0.50 299 8.28 1623L 21FLPOLKHANCOCK H-40 11/ 18/2002 1130 0.40 299 1.67 1623L 21FLPOLKHANCOCK H-2 11/ 18/2002 925 0.40 299 4.54 1623L 21FLPOLKHANCOCK H-16 11/ 18/2002 945 0.20 299 7.69 1623L 21FLPOLKHANCOCK H-12 11/ 18/2002 1305 0.50 299 8.41 1623L 21FLPOLKHANCOCK H-23 11/ 18/2002 1005 0.50 299 9.12 1623L 21FLPOLKHANCOCK H-30 11/ 18/2002 1020 0.50 299 9.44 1623L 21FLPOLKHANCOCK H-55 11/ 18/2002 1210 0.40 299 9.64 1623L 21FLPOLKHANCOCK H-36 11/ 18/2002 1035 0.40 299 9.98 1623L 21FLPOLKHANCOCK H-19 11/ 18/2002 1255 0.50 299 11.04 1623L 21FLPOLKHANCOCK H-25 11/ 18/2002 1240 0.40 299 11.38 1623L 21FLPOLKHANCOCK H-33 11/ 18/2002 1150 0.50 299 11.84 1623L 21FLPOLKHANCOCK H-53 11/ 18/2002 1225 0.50 299 12.11 1623L 21FLTPA 25020276 2/4/2003 940 0.20 299 5.44 D 1623L 21FLPOLKHANCOCK H-41 2/ 13/2003 1040 0.50 299 2.88 1623L 21FLPOLKHANCOCK H-16 2/ 13/2003 825 0.50 299 7.63 1623L 21FLPOLKHANCOCK H-47 2/ 13/2003 1055 0.50 299 9.01 1623L 21FLPOLKHANCOCK H-36 2/ 13/2003 935 0.45 299 10.68 1623L 21FLPOLKHANCOCK H-22 2/ 13/2003 915 0.45 299 11.31 1623L 21FLPOLKHANCOCK H-25 2/ 13/2003 900 0.50 299 11.93 1623L 21FLPOLKHANCOCK H-17 2/ 13/2003 840 0.50 299 12.44 1623L 21FLPOLKHANCOCK H-29 2/ 13/2003 920 0.50 299 12.60 1623L 21FLPOLKHANCOCK H-62 2/ 13/2003 1140 0.50 299 12.63 1623L 21FLPOLKHANCOCK H-30 2/ 13/2003 945 0.50 299 12.69 1623L 21FLPOLKHANCOCK H-59 2/ 13/2003 1120 0.50 299 13.09 1623L 21FLPOLKHANCOCK H-45 2/ 13/2003 1110 0.50 299 13.58 1623L 21FLTPA 25020276 4/22/2003 1110 0.20 299 3.94 D 1623L 21FLPOLKHANCOCK H-4 5/ 20/2003 1115 0.50 299 2.59 1623L 21FLPOLKHANCOCK H-56 5/ 20/2003 920 0.40 299 2.86 1623L 21FLPOLKHANCOCK H-47 5/ 20/2003 900 0.50 299 4.37 1623L 21FLPOLKHANCOCK H-52 5/ 20/2003 950 0.50 299 5.21 1623L 21FLPOLKHANCOCK H-38 5/ 20/2003 1000 0.50 299 5.65 1623L 21FLPOLKHANCOCK H-37 5/ 20/2003 1010 0.50 299 5.68 1623L 21FLPOLKHANCOCK H-40 5/ 20/2003 845 0.50 299 5.98 1623L 21FLPOLKHANCOCK H-53 5/ 20/2003 940 0.50 299 6.46 1623L 21FLPOLKHANCOCK H-24 5/ 20/2003 1150 0.50 299 8.07 1623L 21FLPOLKHANCOCK H-25 5/ 20/2003 1140 0.50 299 8.12 1623L 21FLPOLKHANCOCK H-32 5/ 20/2003 1210 0.50 299 8.37 1623L 21FLPOLKHANCOCK H-31 5/ 20/2003 1200 0.50 299 8.43 1623L 21FLTPA 25020276 8/18/2003 900 0.20 299 6.40 1623L 21FLPOLKHANCOCK H-4 8/ 20/2003 820 0.50 299 1.77DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 94 WBID Station Date Time Depth Storet Code DO (mg/L) R-Code 1623L 21FLPOLKHANCOCK H-23 8/ 20/2003 855 0.50 299 3.89 1623L 21FLPOLKHANCOCK H-24 8/ 20/2003 850 0.50 299 4.38 1623L 21FLPOLKHANCOCK H-37 8/ 20/2003 910 0.50 299 4.96 1623L 21FLPOLKHANCOCK H-18 8/ 20/2003 840 0.50 299 5.19 1623L 21FLPOLKHANCOCK H-39 8/ 20/2003 930 0.50 299 5.46 1623L 21FLPOLKHANCOCK H-38 8/ 20/2003 920 0.50 299 5.61 1623L 21FLPOLKHANCOCK H-47 8/ 20/2003 1050 0.50 299 5.92 1623L 21FLPOLKHANCOCK H-61 8/ 20/2003 1025 0.50 299 6.07 1623L 21FLPOLKHANCOCK H-51 8/ 20/2003 1000 0.50 299 6.36 1623L 21FLPOLKHANCOCK H-59 8/ 20/2003 1015 0.50 299 8.42 1623L 21FLPOLKHANCOCK H-48 8/ 20/2003 1040 0.50 299 8.45 1623L 21FLTPA 25020276 11/3/2003 1040 0.20 299 4.76 1623L 21FLPOLKHANCOCK H-49 11/ 18/2003 920 0.50 299 2.77 1623L 21FLPOLKHANCOCK H-16 11/ 18/2003 1130 0.50 299 7.04 1623L 21FLPOLKHANCOCK H-22 11/ 18/2003 1120 0.50 299 9.12 1623L 21FLPOLKHANCOCK H-30 11/ 18/2003 1110 0.50 299 9.12 1623L 21FLPOLKHANCOCK H-34 11/ 18/2003 945 0.50 299 9.38 1623L 21FLPOLKHANCOCK H-40 11/ 18/2003 955 0.50 299 9.59 1623L 21FLPOLKHANCOCK H-31 11/ 18/2003 1100 0.50 299 10.00 1623L 21FLPOLKHANCOCK H-48 11/ 18/2003 905 0.50 299 10.36 1623L 21FLPOLKHANCOCK H-54 11/ 18/2003 850 0.50 299 10.74 1623L 21FLPOLKHANCOCK H-43 11/ 18/2003 1010 0.50 299 10.81 1623L 21FLPOLKHANCOCK H-3 11/ 18/2003 1140 0.50 299 10.85 1623L 21FLPOLKHANCOCK H-11 11/ 18/2003 1150 0.50 299 11.78 1623L 21FLPOLKHANCOCK H-36 2/ 19/2004 920 0.50 299 9.84 1623L 21FLPOLKHANCOCK H-22 2/ 19/2004 1055 0.50 299 10.14 1623L 21FLPOLKHANCOCK H-62 2/ 19/2004 830 0.50 299 10.57 1623L 21FLPOLKHANCOCK H-44 2/ 19/2004 905 0.50 299 10.67 1623L 21FLPOLKHANCOCK H-59 2/ 19/2004 850 0.50 299 10.93 1623L 21FLPOLKHANCOCK H-37 2/ 19/2004 935 0.50 299 10.95 1623L 21FLPOLKHANCOCK H-34 2/ 19/2004 1000 0.50 299 11.34 1623L 21FLPOLKHANCOCK H-24 2/ 19/2004 1110 0.50 299 11.87 1623L 21FLPOLKHANCOCK H-9 2/ 19/2004 1130 0.50 299 11.89 1623L 21FLPOLKHANCOCK H-33 2/ 19/2004 950 0.50 299 11.94 1623L 21FLPOLKHANCOCK H-30 2/ 19/2004 1045 0.50 299 12.83 1623L 21FLPOLKHANCOCK H-11 2/ 19/2004 1120 0.50 299 14.06 1623L 21FLPOLKHANCOCK H-12 5/5/2004 950 0.50 299 4.65 1623L 21FLPOLKHANCOCK H-36 5/5/2004 915 0.50 299 7.12 1623L 21FLPOLKHANCOCK H-47 5/5/2004 805 0.50 299 7.66 1623L 21FLPOLKHANCOCK H-50 5/5/2004 900 0.50 299 7.69 1623L 21FLPOLKHANCOCK H-43 5/5/2004 910 0.50 299 7.90 1623L 21FLPOLKHANCOCK H-40 5/5/2004 815 0.50 299 8.39 1623L 21FLPOLKHANCOCK H-62 5/5/2004 745 0.50 299 8.43 1623L 21FLPOLKHANCOCK H-3 5/5/2004 940 0.40 299 8.49 1623L 21FLPOLKHANCOCK H-33 5/5/2004 825 0.50 299 8.49 1623L 21FLPOLKHANCOCK H-31 5/5/2004 835 0.50 299 8.79 1623L 21FLPOLKHANCOCK H-54 5/5/2004 755 0.50 299 8.99DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 95 WBID Station Date Time Depth Storet Code DO (mg/L) R-Code 1623L 21FLPOLKHANCOCK H-22 5/5/2004 925 0.40 299 9.03

D: Field measurement.



### Lower Saddle Creek TN Data

WBID Station Date Time Depth Storet Code TN (mg/L) R-Code 1623K 21FLSWFDFLO0038 3/26/1992 1200 8.00 600 2.46 1623K 21FLSWFDFLO0038 7/8/1992 1005 2.00 600 11.02 1623K 112WRD 02294491 8/21/1992 1035 0.50 600 6.42 1623K 21FLSWFDFLO0038 9/22/1992 1420 4.10 600 3.22 1623K 112WRD 02294491 10/29/1992 1645 0.50 600 5.40 1623K 21FLSWFDFLO0038 12/7/1992 1500 2.00 600 2.22 1623K 21FLPOLKP.C. CANAL9 2/ 11/1993 1250 0.50 600 3.43 1623K 21FLPOLKP.C. CANAL9 5/ 13/1993 910 0.20 600 4.24 1623K 21FLPOLKP.C. CANAL9 8/ 17/1993 1320 0.30 600 5.11 1623K 21FLPOLKP.C. CANAL9 11/ 23/1993 910 0.40 600 3.42 1623K 112WRD 02294491 2/9/1994 1015 0.50 600 3.72 1623K 112WRD 02294491 7/14/1994 1000 0.50 600 8.22 1623K 112WRD 02294491 8/9/1994 1610 0.50 600 6.42 1623K 112WRD 02294491 8/23/1994 1020 0.50 600 5.32 1623K 21FLPOLKP.C. CANAL9 8/ 16/1995 1153 0.60 600 1.49 1623K 21FLPOLKP.C. CANAL9 11/21/1995 915 0.50 600 2.55 1623K 21FLPOLKP.C. CANAL9 2/7/1996 928 0.50 600 2.15 1623K 21FLPOLKP.C. CANAL9 5/21/1996 815 0.50 600 5.10 1623K 21FLPOLKP.C. CANAL9 8/14/1996 835 0.50 600 4.59 1623K 21FLPOLKP.C. CANAL9 11/20/1996 825 0.50 600 1.78 1623K 21FLPOLKP.C. CANAL9 2/12/1997 825 0.50 600 4.22 1623K 21FLPOLKP.C. CANAL9 5/20/1997 830 0.50 600 2.67 1623K 21FLPOLKP.C. CANAL9 8/ 12/1997 925 0.80 600 2.33 1623K 21FLPOLKP.C. CANAL9 11/ 5/1997 1112 0.70 600 4.31 1623K 21FLPOLKP.C. CANAL9 5/ 13/1998 1040 0.80 600 3.23 1623K 21FLPOLKP.C. CANAL9 8/ 10/1998 1100 0.70 600 2.45 1623K 21FLSWFDFLO 37 72 0 10/7/1998 900 0.30 600 0.89 1623K 21FLSWFDFLO 37 72 0 11/9/1998 1115 0.30 600 1.20 1623K 21FLPOLKP.C. CANAL9 11/ 12/1998 1050 0.50 600 4.83 1623K 21FLSWFDFLO 37 72 0 12/17/1998 1130 0.30 600 0.39 1623K 21FLSWFDFLO 37 72 0 1/5/1999 1615 0.30 600 1.30 1623K 21FLSWFDFLO 37 72 0 1/7/1999 1355 0.50 600 0.59 1623K 21FLPOLKP.C. CANAL9 2/1/1999 1030 0.25 600 2.49 1623K 21FLSWFDFLO 37 72 0 2/9/1999 1200 0.80 600 0.73 1623K 21FLSWFDFLO 37 72 0 3/1/1999 1650 0.50 600 1.70 1623K 21FLSWFDFLO 37 72 0 3/24/1999 1135 0.50 600 0.88 1623K 21FLSWFDFLO 37 72 0 4/5/1999 1030 0.80 600 1.50 1623K 21FLSWFDFLO 37 72 0 4/6/1999 1245 0.50 600 1.20 1623K 21FLPOLKP.C. CANAL9 4/14/1999 851 0.50 600 2.54 1623K 21FLSWFDFLO 37 72 0 5/10/1999 1445 0.65 600 1.00DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 96 WBID Station Date Time Depth Storet Code TN (mg/L) R-Code 1623K 21FLSWFDFLO 37 72 0 6/9/1999 1000 0.75 600 1.30 1623K 21FLPOLKP.C. CANAL9 7/14/1999 940 0.50 600 2.66 1623K 21FLSWFDFLO 37 72 0 7/17/1999 925 0.30 600 1.30 1623K 21FLSWFDFLO 37 72 0 8/16/1999 1030 0.50 600 1.00 1623K 21FLSWFDFLO 37 72 0 9/16/1999 1040 0.50 600 1.90 1623K 21FLSWFDFLO 37 72 0 10/4/1999 1410 0.50 600 1.10 1623K 21FLPOLKP.C. CANAL9 1/13/2000 950 0.50 600 1.82 1623K 21FLPOLKP.C. CANAL9 4/17/2000 900 0.50 600 5.05 1623K 21FLSWFDFLO 37 72 0 5/3/2000 1100 0.50 600 1.15 1623K 21FLPOLKP.C. CANAL9 7/ 18/2000 710 0.30 600 1.92 1623K 21FLPOLKP.C. CANAL9 10/ 5/2000 1000 0.50 600 2.65 1623K 21FLPOLKP.C. CANAL9 1/9/2001 1245 0.20 600 1.04 1623K 21FLPOLKP.C. CANAL9 3/6/2001 1100 0.30 600 1.26 1623K 21FLPOLKP.C. CANAL9 10/ 29/2001 1330 0.50 600 2.11 1623K 21FLSWFDFLO 37 72 0 12/10/2001 1020 0.50 600 2.31 1623K 21FLSWFDFLO 37 72 0 1/8/2002 1035 0.50 600 2.26 1623K 21FLPOLKP.C. CANAL9 1/ 15/2002 1145 0.33 600 1.99 1623K 21FLSWFDFLO 37 72 0 2/6/2002 915 0.50 600 2.27 1623K 21FLSWFDFLO 37 72 0 3/4/2002 1110 0.50 600 2.34 1623K 21FLSWFDFLO 37 72 0 4/2/2002 1115 0.50 600 2.59 1623K 21FLPOLKP.C. CANAL9 4/ 17/2002 1055 0.15 600 1.54 1623K 21FLSWFDFLO 37 72 0 5/6/2002 1050 0.50 600 3.24 1623K 21FLSWFDFLO 37 72 0 7/4/2002 1530 0.50 600 2.50 1623K 21FLPOLKP.C. CANAL9 7/ 24/2002 930 0.50 600 4.36 1623K 21FLSWFDFLO 37 72 0 9/5/2002 1700 0.50 600 3.13 1623K 21FLSWFDFLO 37 72 0 10/1/2002 1200 0.50 600 3.19 1623K 21FLPOLKP.C. CANAL9 10/ 23/2002 930 0.30 600 3.60 1623K 21FLSWFDFLO 37 72 0 11/4/2002 1040 0.50 600 3.11 1623K 21FLSWFDFLO 37 72 0 12/4/2002 1050 0.50 600 3.16 1623K 21FLPOLKP.C. CANAL9 1/ 28/2003 1005 0.50 600 2.07 1623K 21FLPOLKP.C. CANAL9 4/ 16/2003 930 0.50 600 4.58 1623K 21FLPOLKP.C. CANAL9 7/ 23/2003 915 0.50 600 6.42 1623K 21FLPOLKP.C. CANAL9 10/ 8/2003 1020 0.50 600 2.74 1623K 21FLPOLKP.C. CANAL9 1/7/2004 940 0.40 600 4.11 1623K 21FLPOLKP.C. CANAL9 4/ 15/2004 955 0.25 600 5.03DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 97 Lower Saddle Creek TP Data

WBID Station Date Time Depth Storet Code TP (mg/L) R-Code 1623K 21FLSWFDFLO0038 3/26/1992 1200 8.00 665 0.07 1623K 21FLSWFDFLO0038 7/8/1992 1005 2.00 665 0.88 1623K 112WRD 02294491 8/21/1992 1035 0.50 665 0.42 1623K 21FLSWFDFLO0038 9/22/1992 1420 4.10 665 0.26 1623K 112WRD 02294491 9/25/1992 1130 0.50 665 0.17 1623K 112WRD 02294491 10/29/1992 1645 0.50 665 0.76 1623K 21FLSWFDFLO0038 12/7/1992 1500 2.00 665 0.42 1623K 21FLPOLKP.C. CANAL9 2/ 11/1993 1250 0.50 665 0.28 1623K 112WRD 02294491 4/16/1993 1150 0.50 665 0.47 1623K 21FLPOLKP.C. CANAL9 5/ 13/1993 910 0.20 665 0.73 1623K 112WRD 02294491 7/9/1993 1300 0.50 665 1.10 1623K 21FLPOLKP.C. CANAL9 8/ 17/1993 1320 0.30 665 0.63 1623K 112WRD 02294491 9/23/1993 1130 0.50 665 0.35 1623K 112WRD 02294491 10/13/1993 1300 0.50 665 0.30 1623K 21FLPOLKP.C. CANAL9 11/ 23/1993 910 0.40 665 1.17 1623K 112WRD 02294491 2/9/1994 1015 0.50 665 0.24 1623K 112WRD 02294491 7/14/1994 1000 0.50 665 0.20 1623K 112WRD 02294491 8/9/1994 1610 0.50 665 0.15 1623K 112WRD 02294491 8/23/1994 1020 0.50 665 0.33 1623K 21FLPOLKP.C. CANAL9 8/ 16/1995 1153 0.60 665 0.40 1623K 21FLPOLKP.C. CANAL9 11/21/1995 915 0.50 665 0.58 1623K 21FLPOLKP.C. CANAL9 2/7/1996 928 0.33 665 0.30 1623K 21FLPOLKP.C. CANAL9 5/ 21/1996 815 0.33 665 0.62 1623K 21FLPOLKP.C. CANAL9 8/ 14/1996 835 0.33 665 0.65 1623K 21FLPOLKP.C. CANAL9 11/ 20/1996 825 0.33 665 0.38 1623K 21FLPOLKP.C. CANAL9 2/12/1997 825 0.50 665 0.30 1623K 21FLPOLKP.C. CANAL9 5/20/1997 830 0.50 665 0.58 1623K 21FLSWFDFLO 37 72 0 8/4/1997 1200 1.00 665 0.39 1623K 21FLPOLKP.C. CANAL9 8/ 12/1997 925 0.80 665 0.21 1623K 21FLSWFDFLO 37 72 0 9/10/1997 1030 1.00 665 0.15 1623K 21FLSWFDFLO 37 72 0 10/6/1997 1130 1.00 665 0.39 1623K 21FLSWFDFLO 37 72 0 11/3/1997 1040 0.30 665 0.45 1623K 21FLPOLKP.C. CANAL9 11/ 5/1997 1112 0.70 665 0.35 1623K 21FLSWFDFLO 37 72 0 1/22/1998 1330 0.50 665 0.03 1623K 21FLSWFDFLO 37 72 0 2/2/1998 1040 0.70 665 0.55 1623K 21FLPOLKP.C. CANAL9 2/ 10/1998 1130 1.40 665 0.60 1623K 21FLSWFDFLO 37 72 0 3/2/1998 1015 0.30 665 0.65 1623K 21FLSWFDFLO 37 72 0 3/26/1998 1030 0.50 665 0.02 1623K 21FLSWFDFLO 37 72 0 4/6/1998 1010 0.30 665 0.51 1623K 21FLSWFDFLO 37 72 0 4/15/1998 1125 0.50 665 0.03 1623K 21FLSWFDFLO 37 72 0 5/4/1998 1215 0.30 665 0.60 1623K 21FLPOLKP.C. CANAL9 5/ 13/1998 1040 0.80 665 0.57 1623K 21FLSWFDFLO 37 72 0 5/15/1998 1100 0.50 665 0.04 1623K 21FLSWFDFLO 37 72 0 6/1/1998 1045 0.30 665 0.40 1623K 21FLSWFDFLO 37 72 0 6/16/1998 1345 0.50 665 0.02DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 98 WBID Station Date Time Depth Storet Code TP (mg/L) R-Code 1623K 21FLSWFDFLO 37 72 0 7/6/1998 1100 0.30 665 0.71 1623K 21FLSWFDFLO 37 72 0 7/28/1998 1230 0.50 665 0.02 1623K 21FLSWFDFLO 37 72 0 8/3/1998 1130 0.60 665 0.58 1623K 21FLPOLKP.C. CANAL9 8/ 10/1998 1100 0.70 665 0.47 1623K 21FLSWFDFLO 37 72 0 8/11/1998 1230 0.50 665 0.03 1623K 21FLSWFDFLO 37 72 0 9/8/1998 1015 0.30 665 0.60 1623K 21FLSWFDFLO 37 72 0 9/10/1998 1245 0.50 665 0.01 1623K 21FLSWFDFLO 37 72 0 10/7/1998 900 0.30 665 0.31 1623K 21FLSWFDFLO 37 72 0 10/12/1998 1545 0.50 665 0.03 1623K 21FLSWFDFLO 37 72 0 11/9/1998 1115 0.30 665 0.29 1623K 21FLPOLKP.C. CANAL9 11/ 12/1998 1050 0.50 665 0.66 1623K 21FLSWFDFLO 37 72 0 12/9/1998 1355 0.50 665 0.02 1623K 21FLSWFDFLO 37 72 0 12/17/1998 1130 0.30 665 0.24 1623K 21FLSWFDFLO 37 72 0 1/5/1999 1615 0.30 665 0.33 1623K 21FLSWFDFLO 37 72 0 1/7/1999 1355 . 665 0.03 1623K 21FLPOLKP.C. CANAL9 2/1/1999 1030 0.25 665 0.44 1623K 21FLSWFDFLO 37 72 0 2/9/1999 1200 0.80 665 0.28 1623K 21FLSWFDFLO 37 72 0 3/1/1999 1650 0.50 665 0.15 1623K 21FLSWFDFLO 37 72 0 3/24/1999 1135 0.50 665 0.03 1623K 21FLSWFDFLO 37 72 0 4/5/1999 1030 0.80 665 0.31 1623K 21FLSWFDFLO 37 72 0 4/6/1999 1245 0.50 665 0.02 1623K 21FLPOLKP.C. CANAL9 4/14/1999 851 0.50 665 0.72 1623K 21FLSWFDFLO 37 72 0 5/10/1999 1445 0.65 665 0.44 1623K 21FLSWFDFLO 37 72 0 6/9/1999 1000 0.75 665 0.50 1623K 21FLPOLKP.C. CANAL9 7/14/1999 940 0.50 665 0.33 1623K 21FLSWFDFLO 37 72 0 7/17/1999 925 0.30 665 0.16 1623K 21FLSWFDFLO 37 72 0 8/16/1999 1030 0.50 665 0.18 1623K 21FLSWFDFLO 37 72 0 9/16/1999 1040 0.50 665 0.56 1623K 21FLSWFDFLO 37 72 0 10/4/1999 1410 0.50 665 0.18 1623K 21FLPOLKP.C. CANAL9 10/ 5/1999 950 1.63 665 0.37 1623K 21FLSWFDFLO 37 72 0 11/1/1999 930 0.50 665 0.05 1623K 21FLSWFDFLO 37 72 0 12/8/1999 1000 0.50 665 0.10 1623K 21FLSWFDFLO 37 72 0 1/5/2000 1030 0.50 665 0.16 1623K 21FLPOLKP.C. CANAL9 1/13/2000 950 0.50 665 0.15 1623K 21FLSWFDFLO 37 72 0 2/8/2000 1130 0.50 665 0.33 1623K 21FLSWFDFLO 37 72 0 3/15/2000 1100 0.50 665 0.21 1623K 21FLPOLKP.C. CANAL9 4/17/2000 900 0.50 665 0.69 1623K 21FLSWFDFLO 37 72 0 5/3/2000 1100 0.50 665 0.07 1623K 21FLSWFDFLO 37 72 0 5/11/2000 1000 0.50 665 0.64 1623K 21FLSWFDFLO 37 72 0 6/6/2000 1155 0.50 665 0.03 1623K 21FLSWFDFLO 37 72 0 6/8/2000 1100 0.50 665 0.96 1623K 21FLSWFDFLO 37 72 0 7/6/2000 1445 0.50 665 0.40 1623K 21FLPOLKP.C. CANAL9 7/ 18/2000 710 0.30 665 0.86 1623K 21FLSWFDFLO 37 72 0 8/1/2000 1145 0.50 665 0.03 1623K 21FLSWFDFLO 37 72 0 8/8/2000 1500 0.50 665 0.33 1623K 21FLSWFDFLO 37 72 0 9/12/2000 1000 0.50 665 0.52 1623K 21FLSWFDFLO 37 72 0 9/13/2000 1145 0.50 665 0.04DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 99 WBID Station Date Time Depth Storet Code TP (mg/L) R-Code 1623K 21FLSWFDFLO 37 72 0 10/3/2000 1510 0.50 665 0.39 1623K 21FLPOLKP.C. CANAL9 10/ 5/2000 1000 0.50 665 1.90 1623K 21FLSWFDFLO 37 72 0 10/17/2000 1530 0.50 665 0.03 1623K 21FLSWFDFLO 37 72 0 11/1/2000 1120 0.50 665 0.02 1623K 21FLSWFDFLO 37 72 0 11/6/2000 1430 0.50 665 1.96 1623K 21FLSWFDFLO 37 72 0 12/6/2000 1330 0.50 665 1.27 1623K 21FLPOLKP.C. CANAL9 1/9/2001 1245 0.20 665 0.35 1623K 21FLSWFDFLO 37 72 0 2/7/2001 1545 0.55 665 3.21 1623K 21FLPOLKP.C. CANAL9 3/6/2001 1100 0.30 665 0.62 1623K 21FLSWFDFLO 37 72 0 3/7/2001 945 0.50 665 2.95 1623K 21FLSWFDFLO 37 72 0 4/3/2001 1015 0.50 665 1.42 1623K 21FLSWFDFLO 37 72 0 5/9/2001 1040 0.50 665 1.20 1623K 21FLSWFDFLO 37 72 0 6/5/2001 940 0.32 665 1.38 1623K 21FLSWFDFLO 37 72 0 8/9/2001 1330 0.50 665 10.50 1623K 21FLSWFDFLO 37 72 0 9/4/2001 1050 0.50 665 2.17 1623K 21FLSWFDFLO 37 72 0 10/2/2001 1050 0.50 665 0.72 1623K 21FLPOLKP.C. CANAL9 10/ 29/2001 1330 0.50 665 1.01 1623K 21FLSWFDFLO 37 72 0 12/10/2001 1020 0.50 665 0.88 1623K 21FLSWFDFLO 37 72 0 1/8/2002 1035 0.50 665 0.92 1623K 21FLPOLKP.C. CANAL9 1/ 15/2002 1145 0.33 665 0.53 1623K 21FLSWFDFLO 37 72 0 2/6/2002 915 0.50 665 0.88 1623K 21FLSWFDFLO 37 72 0 3/4/2002 1110 0.50 665 0.75 1623K 21FLSWFDFLO 37 72 0 4/2/2002 1115 0.50 665 0.66 1623K 21FLPOLKP.C. CANAL9 4/ 17/2002 1055 0.15 665 1.06 1623K 21FLSWFDFLO 37 72 0 5/6/2002 1050 0.50 665 0.51 1623K 21FLSWFDFLO 37 72 0 7/4/2002 1530 0.50 665 0.92 1623K 21FLPOLKP.C. CANAL9 7/ 24/2002 930 0.50 665 0.61 1623K 21FLSWFDFLO 37 72 0 9/5/2002 1700 0.50 665 0.80 1623K 21FLSWFDFLO 37 72 0 10/1/2002 1200 0.50 665 0.38 1623K 21FLPOLKP.C. CANAL9 10/ 23/2002 930 0.30 665 0.67 1623K 21FLSWFDFLO 37 72 0 11/4/2002 1040 0.50 665 0.76 1623K 21FLSWFDFLO 37 72 0 12/4/2002 1050 0.50 665 0.21 1623K 21FLPOLKP.C. CANAL9 1/ 28/2003 1005 0.50 665 0.53 1623K 21FLTPA 27552158149358 2/5/2003 1345 0.20 665 0.73 1623K 21FLPOLKP.C. CANAL9 4/ 16/2003 930 0.50 665 1.01 1623K 21FLTPA 27552158149358 4/22/2003 1000 0.20 665 1.10 1623K 21FLPOLKP.C. CANAL9 7/ 23/2003 915 0.50 665 0.97 1623K 21FLTPA 27552158149358 8/19/2003 950 0.20 665 0.66 1623K 21FLPOLKP.C. CANAL9 10/ 8/2003 1020 0.50 665 0.85 1623K 21FLTPA 27552158149358 11/4/2003 1145 0.20 665 0.78 1623K 21FLPOLKP.C. CANAL9 1/7/2004 940 0.40 665 1.04 1623K 21FLPOLKP.C. CANAL9 4/ 15/2004 955 0.25 665 1.23DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 100 Lower Saddle Creek Chlorophyll a Data

WBID Station Date Time Depth Storet Code Chl a ( μ g/L) R-Code 1623K 21FLPOLKP.C. CANAL9 8/ 16/1995 1153 1.97 32210 118.2 1623K 21FLPOLKP.C. CANAL9 11/ 21/1995 915 0.33 32210 109.2 1623K 21FLPOLKP.C. CANAL9 2/ 7/1996 928 0.33 32210 42.8 1623K 21FLPOLKP.C. CANAL9 5/ 21/1996 815 0.33 32210 201.9 1623K 21FLPOLKP.C. CANAL9 8/ 14/1996 835 0.33 32210 157.7 1623K 21FLPOLKP.C. CANAL9 11/ 20/1996 825 0.33 32210 59.5 1623K 21FLPOLKP.C. CANAL9 2/ 12/1997 825 2.95 32210 141.8 1623K 21FLPOLKP.C. CANAL9 5/ 20/1997 830 1.31 32210 110.1 1623K 21FLSWFDFLO 37 72 0 8/4/1997 1200 1.00 32209 114.9 1623K 21FLPOLKP.C. CANAL9 8/ 12/1997 925 2.62 32210 71.7 1623K 21FLSWFDFLO 37 72 0 9/10/1997 1030 1.00 32209 61.4 1623K 21FLSWFDFLO 37 72 0 10/6/1997 1130 1.00 32209 43.0 1623K 21FLSWFDFLO 37 72 0 11/3/1997 1040 0.30 32209 112.9 1623K 21FLPOLKP.C. CANAL9 11/ 5/1997 1112 2.30 32210 136.0 1623K 21FLSWFDFLO 37 72 0 12/1/1997 1035 1.40 32210 195.0 1623K 21FLSWFDFLO 37 72 0 12/1/1997 1035 1.40 32209 96.1 1623K 21FLSWFDFLO 37 72 0 1/22/1998 1330 0.50 32209 5.3 1623K 21FLSWFDFLO 37 72 0 2/2/1998 1040 0.70 32209 53.4 1623K 21FLSWFDFLO 37 72 0 3/2/1998 1015 0.30 32209 229.6 1623K 21FLSWFDFLO 37 72 0 3/26/1998 1030 0.50 32209 1.6 1623K 21FLSWFDFLO 37 72 0 4/6/1998 1010 0.30 32209 133.5 1623K 21FLSWFDFLO 37 72 0 4/15/1998 1125 0.50 32209 1.0 1623K 21FLSWFDFLO 37 72 0 5/4/1998 1215 0.30 32209 80.1 1623K 21FLSWFDFLO 37 72 0 5/15/1998 1100 0.50 32209 1.6 1623K 21FLSWFDFLO 37 72 0 6/1/1998 1045 0.30 32210 166.0 1623K 21FLSWFDFLO 37 72 0 6/1/1998 1045 0.30 32209 138.8 1623K 21FLSWFDFLO 37 72 0 6/16/1998 1345 0.50 32209 4.8 1623K 21FLSWFDFLO 37 72 0 7/6/1998 1100 0.30 32209 267.0 1623K 21FLSWFDFLO 37 72 0 7/28/1998 1230 0.50 32209 4.3 1623K 21FLSWFDFLO 37 72 0 8/3/1998 1130 0.60 32209 96.1 1623K 21FLSWFDFLO 37 72 0 8/11/1998 1230 0.50 32210 5.0 1623K 21FLSWFDFLO 37 72 0 8/11/1998 1230 0.50 32209 1.0 1623K 21FLSWFDFLO 37 72 0 9/8/1998 1015 0.30 32209 96.1 1623K 21FLSWFDFLO 37 72 0 9/10/1998 1245 0.50 32209 3.7 1623K 21FLSWFDFLO 37 72 0 10/7/1998 900 0.30 32209 93.5 1623K 21FLSWFDFLO 37 72 0 10/12/1998 1545 0.50 32209 10.7 1623K 21FLSWFDFLO 37 72 0 11/9/1998 1115 0.30 32209 203.0 1623K 21FLSWFDFLO 37 72 0 11/9/1998 1320 0.50 32209 3.7 1623K 21FLSWFDFLO 37 72 0 12/9/1998 1355 0.50 32209 1.6 1623K 21FLSWFDFLO 37 72 0 12/17/1998 1130 0.30 32209 98.6 1623K 21FLSWFDFLO 37 72 0 1/5/1999 1615 0.30 32209 223.0 1623K 21FLSWFDFLO 37 72 0 1/7/1999 1355 0.50 32209 83.5 1623K 21FLPOLKP.C. CANAL9 2/ 1/1999 1030 0.25 32223 52.1 1623K 21FLSWFDFLO 37 72 0 2/9/1999 1200 0.80 32209 79.3 1623K 21FLSWFDFLO 37 72 0 3/1/1999 1650 0.50 32209 110.0DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 101 WBID Station Date Time Depth Storet Code Chl a ( μ g/L) R-Code 1623K 21FLSWFDFLO 37 72 0 3/24/1999 1135 0.50 32209 7.4 1623K 21FLSWFDFLO 37 72 0 4/5/1999 1030 0.80 32209 172.1 1623K 21FLSWFDFLO 37 72 0 4/6/1999 1245 0.50 32209 31.3 1623K 21FLPOLKP.C. CANAL9 4/ 14/1999 851 0.50 32223 52.1 1623K 21FLSWFDFLO 37 72 0 5/10/1999 1445 0.65 32209 229.0 1623K 21FLSWFDFLO 37 72 0 6/9/1999 1000 0.75 32209 310.0 1623K 21FLPOLKP.C. CANAL9 7/ 14/1999 940 0.50 32223 108.1 1623K 21FLSWFDFLO 37 72 0 7/17/1999 925 0.30 32209 88.1 1623K 21FLSWFDFLO 37 72 0 8/16/1999 1030 0.50 32209 115.0 1623K 21FLSWFDFLO 37 72 0 9/16/1999 1040 0.50 32209 333.0 1623K 21FLSWFDFLO 37 72 0 10/4/1999 1410 0.50 32209 350.0 1623K 21FLSWFDFLO 37 72 0 11/1/1999 930 0.50 32209 71.8 1623K 21FLSWFDFLO 37 72 0 12/8/1999 1000 0.50 32209 63.1 1623K 21FLSWFDFLO 37 72 0 1/5/2000 1030 0.50 32209 45.4 1623K 21FLPOLKP.C. CANAL9 1/ 13/2000 950 0.50 32223 32.0 1623K 21FLSWFDFLO 37 72 0 2/8/2000 1130 0.50 32209 32.0 1623K 21FLSWFDFLO 37 72 0 3/15/2000 1100 0.50 32209 13.4 1623K 21FLPOLKP.C. CANAL9 4/ 17/2000 900 0.50 32223 100.2 1623K 21FLSWFDFLO 37 72 0 5/3/2000 1100 0.50 32209 1.0 1623K 21FLSWFDFLO 37 72 0 5/11/2000 1000 0.50 32209 117.0 1623K 21FLSWFDFLO 37 72 0 6/6/2000 1155 0.50 32209 1.0 1623K 21FLSWFDFLO 37 72 0 6/8/2000 1100 0.50 32209 512.0 1623K 21FLSWFDFLO 37 72 0 7/6/2000 1340 0.50 32209 3.2 1623K 21FLSWFDFLO 37 72 0 7/6/2000 1445 0.50 32209 66.8 1623K 21FLPOLKP.C. CANAL9 7/ 18/2000 710 0.30 32223 32.4 1623K 21FLSWFDFLO 37 72 0 8/1/2000 1145 0.50 32209 1.1 1623K 21FLSWFDFLO 37 72 0 8/8/2000 1500 0.50 32209 117.0 1623K 21FLSWFDFLO 37 72 0 9/12/2000 1000 0.50 32209 21.4 1623K 21FLSWFDFLO 37 72 0 9/13/2000 1145 0.50 32209 6.4 1623K 21FLSWFDFLO 37 72 0 10/3/2000 1510 0.50 32209 14.7 1623K 21FLPOLKP.C. CANAL9 10/ 5/2000 1000 0.50 32223 1.0 1623K 21FLSWFDFLO 37 72 0 10/17/2000 1530 0.50 32209 3.6 1623K 21FLSWFDFLO 37 72 0 11/1/2000 1120 0.50 32209 1.0 1623K 21FLSWFDFLO 37 72 0 11/6/2000 1430 0.50 32209 363.0 1623K 21FLSWFDFLO 37 72 0 12/6/2000 1330 0.50 32209 246.0 1623K 21FLPOLKP.C. CANAL9 1/ 9/2001 1245 0.20 32223 3.2 1623K 21FLSWFDFLO 37 72 0 2/7/2001 1545 0.55 32209 612.0 1623K 21FLPOLKP.C. CANAL9 3/ 6/2001 1100 0.30 32223 4.0 1623K 21FLSWFDFLO 37 72 0 3/7/2001 945 0.50 32209 260.0 1623K 21FLSWFDFLO 37 72 0 4/3/2001 1015 0.50 32209 240.0 1623K 21FLSWFDFLO 37 72 0 5/9/2001 1040 0.50 32209 58.7 1623K 21FLSWFDFLO 37 72 0 6/5/2001 940 0.32 32209 62.7 1623K 21FLSWFDFLO 37 72 0 8/9/2001 1330 0.50 32209 1.0 1623K 21FLSWFDFLO 37 72 0 9/4/2001 1050 0.50 32209 21.4 1623K 21FLSWFDFLO 37 72 0 10/2/2001 1050 0.50 32209 17.4 1623K 21FLPOLKP.C. CANAL9 10/ 29/2001 1330 0.50 32223 115.3 1623K 21FLSWFDFLO 37 72 0 12/10/2001 1020 0.50 32209 44.1DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 102 WBID Station Date Time Depth Storet Code Chl a ( μ g/L) R-Code 1623K 21FLSWFDFLO 37 72 0 1/8/2002 1035 0.50 32209 29.7 1623K 21FLPOLKP.C. CANAL9 1/ 15/2002 1145 0.33 32223 40.1 1623K 21FLSWFDFLO 37 72 0 2/6/2002 915 0.50 32209 36.3 1623K 21FLSWFDFLO 37 72 0 3/4/2002 1110 0.50 32209 104.7 1623K 21FLSWFDFLO 37 72 0 4/2/2002 1115 0.50 32209 59.1 1623K 21FLPOLKP.C. CANAL9 4/ 17/2002 1055 0.15 32223 24.8 1623K 21FLSWFDFLO 37 72 0 5/6/2002 1050 0.50 32209 151.0 1623K 21FLSWFDFLO 37 72 0 7/4/2002 1530 0.50 32209 91.8 1623K 21FLPOLKP.C. CANAL9 7/ 24/2002 930 0.50 32223 108.1 1623K 21FLSWFDFLO 37 72 0 9/5/2002 1700 0.50 32209 120.0 1623K 21FLSWFDFLO 37 72 0 10/1/2002 1200 0.50 32209 133.0 1623K 21FLPOLKP.C. CANAL9 10/ 23/2002 930 0.30 32223 76.1 1623K 21FLSWFDFLO 37 72 0 11/4/2002 1040 0.50 32209 241.0 1623K 21FLSWFDFLO 37 72 0 12/4/2002 1050 0.50 32209 90.6 1623K 21FLTPA 27552158149358 2/5/2003 1345 0.20 32209 100.0 1623K 21FLTPA 27552158149358 4/22/2003 1000 0.20 32209 240.0 1623K 21FLTPA 27552158149358 8/19/2003 950 0.20 32209 260.0 1623K 21FLTPA 27552158149358 11/4/2003 1145 0.20 32209 54.0 1623K 21FLPOLKP.C. CANAL9 4/ 15/2004 955 0.25 32210 148.0



### Lower Saddle Creek Dissolved Oxygen Data

WBID Station Date Time Depth Storet Code DO (mg/L) R-Code 1623K 21FLSWFDFLO0038 3/26/1992 1200 0.80 299 5.12 1623K 21FLSWFDFLO0038 7/8/1992 1045 2.00 299 1.43 1623K 21FLSWFDFLO0038 9/22/1992 1420 4.59 299 1.67 1623K 112WRD 02294491 9/25/1992 1130 0.50 300 7.60 1623K 112WRD 02294491 10/29/1992 1645 0.50 300 1.40 1623K 21FLSWFDFLO0038 12/7/1992 1500 1.64 299 12.29 1623K 21FLPOLKP.C. CANAL9 2/ 11/1993 1250 0.50 299 6.70 1623K 112WRD 02294491 4/16/1993 1150 0.50 300 8.00 1623K 21FLPOLKP.C. CANAL9 5/ 13/1993 910 0.20 299 5.00 1623K 112WRD 02294491 7/9/1993 1300 0.50 300 4.00 1623K 21FLPOLKP.C. CANAL9 8/ 17/1993 1320 0.30 299 2.60 1623K 112WRD 02294491 9/23/1993 1130 0.50 300 5.70 1623K 112WRD 02294491 10/13/1993 1300 0.50 300 7.20 1623K 21FLPOLKP.C. CANAL9 11/ 23/1993 910 0.40 299 1.70 1623K 112WRD 02294491 8/9/1994 1610 0.50 300 13.50 1623K 112WRD 02294491 8/23/1994 1020 0.50 300 7.90 1623K 21FLPOLKP.C. CANAL9 8/ 16/1995 1153 0.60 299 5.40 1623K 21FLPOLKP.C. CANAL9 11/ 21/1995 915 0.33 299 6.80 1623K 21FLPOLKP.C. CANAL9 2/7/1996 928 0.33 299 12.50 1623K 21FLPOLKP.C. CANAL9 5/ 21/1996 815 0.33 299 4.10 1623K 21FLPOLKP.C. CANAL9 8/ 14/1996 835 0.33 299 5.10 1623K 21FLPOLKP.C. CANAL9 11/ 20/1996 825 0.33 299 8.80 1623K 21FLPOLKP.C. CANAL9 2/ 12/1997 825 0.00 299 10.34DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 103 WBID Station Date Time Depth Storet Code DO (mg/L) R-Code 1623K 21FLPOLKP.C. CANAL9 5/ 20/1997 830 0.00 299 6.04 1623K 21FLSWFDFLO 37 72 0 8/4/1997 1200 1.00 299 6.39 1623K 21FLPOLKP.C. CANAL9 8/ 12/1997 925 0.80 299 6.88 1623K 21FLSWFDFLO 37 72 0 9/10/1997 1030 1.00 299 6.44 1623K 21FLSWFDFLO 37 72 0 10/6/1997 1130 1.00 299 4.71 1623K 21FLSWFDFLO 37 72 0 11/3/1997 1040 0.30 299 6.68 1623K 21FLPOLKP.C. CANAL9 11/ 5/1997 1112 0.70 299 11.03 1623K 21FLSWFDFLO 37 72 0 12/1/1997 1035 1.40 299 7.18 1623K 21FLSWFDFLO 37 72 0 1/22/1998 1330 S 299 7.98 1623K 21FLSWFDFLO 37 72 0 2/2/1998 1040 0.70 299 8.94 1623K 21FLPOLKP.C. CANAL9 2/ 10/1998 1130 1.40 299 12.18 1623K 21FLSWFDFLO 37 72 0 3/2/1998 1015 0.30 299 7.83 1623K 21FLSWFDFLO 37 72 0 3/26/1998 1030 B 299 7.57 1623K 21FLSWFDFLO 37 72 0 4/6/1998 1010 0.30 299 6.89 1623K 21FLSWFDFLO 37 72 0 4/15/1998 1125 B 299 6.70 1623K 21FLSWFDFLO 37 72 0 5/4/1998 1215 0.30 299 6.13 1623K 21FLPOLKP.C. CANAL9 5/ 13/1998 1040 0.80 299 4.76 1623K 21FLSWFDFLO 37 72 0 5/15/1998 1100 S 299 5.32 1623K 21FLSWFDFLO 37 72 0 6/1/1998 1045 0.30 299 6.60 1623K 21FLSWFDFLO 37 72 0 6/16/1998 1345 S 299 9.35 1623K 21FLSWFDFLO 37 72 0 7/6/1998 1100 0.30 299 1.70 1623K 21FLSWFDFLO 37 72 0 7/28/1998 1230 S 299 2.95 1623K 21FLSWFDFLO 37 72 0 8/3/1998 1130 0.60 299 4.00 1623K 21FLPOLKP.C. CANAL9 8/ 10/1998 1100 0.70 299 5.91 1623K 21FLSWFDFLO 37 72 0 8/11/1998 1230 S 299 9.36 1623K 21FLSWFDFLO 37 72 0 9/8/1998 1015 0.30 299 2.19 1623K 21FLSWFDFLO 37 72 0 9/10/1998 1245 S 299 7.17 1623K 21FLSWFDFLO 37 72 0 10/7/1998 900 0.30 299 5.77 1623K 21FLSWFDFLO 37 72 0 10/12/1998 1545 B 299 5.22 1623K 21FLSWFDFLO 37 72 0 11/9/1998 1320 S 299 3.54 1623K 21FLPOLKP.C. CANAL9 11/ 12/1998 1050 0.50 299 7.20 1623K 21FLSWFDFLO 37 72 0 12/9/1998 1355 S 299 7.44 1623K 21FLSWFDFLO 37 72 0 12/17/1998 1130 0.30 299 7.89 1623K 21FLSWFDFLO 37 72 0 1/5/1999 1615 0.30 299 7.74 1623K 21FLSWFDFLO 37 72 0 1/7/1999 1355 S 299 7.61 1623K 21FLPOLKP.C. CANAL9 2/1/1999 1030 0.25 299 8.36 1623K 21FLSWFDFLO 37 72 0 2/9/1999 1200 0.80 299 7.75 1623K 21FLSWFDFLO 37 72 0 3/1/1999 1650 0.50 299 8.31 1623K 21FLSWFDFLO 37 72 0 3/24/1999 1135 S 299 9.06 1623K 21FLSWFDFLO 37 72 0 4/5/1999 1030 0.80 299 5.05 1623K 21FLSWFDFLO 37 72 0 4/6/1999 1245 S 299 3.14 1623K 21FLPOLKP.C. CANAL9 4/14/1999 851 0.50 299 6.07 1623K 21FLSWFDFLO 37 72 0 5/10/1999 1445 0.65 299 4.61 1623K 21FLSWFDFLO 37 72 0 6/9/1999 1000 0.75 299 4.89 1623K 21FLPOLKP.C. CANAL9 7/14/1999 940 0.50 299 5.49 1623K 21FLSWFDFLO 37 72 0 7/17/1999 925 0.30 299 4.42 1623K 21FLSWFDFLO 37 72 0 8/16/1999 1030 0.50 299 2.92DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 104 WBID Station Date Time Depth Storet Code DO (mg/L) R-Code 1623K 21FLSWFDFLO 37 72 0 9/16/1999 1040 0.50 299 3.15 1623K 21FLSWFDFLO 37 72 0 10/4/1999 1410 0.50 299 7.97 1623K 21FLSWFDFLO 37 72 0 11/1/1999 930 0.50 299 7.61 1623K 21FLSWFDFLO 37 72 0 12/8/1999 1000 0.50 299 7.00 1623K 21FLSWFDFLO 37 72 0 1/5/2000 1030 0.50 299 9.73 1623K 21FLPOLKP.C. CANAL9 1/13/2000 950 0.50 299 8.72 1623K 21FLSWFDFLO 37 72 0 2/8/2000 1130 0.50 299 11.61 1623K 21FLSWFDFLO 37 72 0 3/15/2000 1100 0.50 299 6.81 1623K 21FLPOLKP.C. CANAL9 4/17/2000 900 0.50 299 5.35 1623K 21FLSWFDFLO 37 72 0 5/3/2000 1100 0.50 299 8.42 1623K 21FLSWFDFLO 37 72 0 5/11/2000 1000 0.50 299 4.51 1623K 21FLSWFDFLO 37 72 0 6/6/2000 1155 S 299 12.49 1623K 21FLSWFDFLO 37 72 0 6/8/2000 1100 0.50 299 2.44 1623K 21FLSWFDFLO 37 72 0 7/6/2000 1340 S 299 9.45 1623K 21FLPOLKP.C. CANAL9 7/ 18/2000 710 0.30 299 1.21 1623K 21FLSWFDFLO 37 72 0 8/1/2000 1145 S 299 10.91 1623K 21FLSWFDFLO 37 72 0 8/8/2000 1500 0.50 299 1.75 1623K 21FLSWFDFLO 37 72 0 9/12/2000 1000 0.50 299 4.44 1623K 21FLSWFDFLO 37 72 0 9/13/2000 1145 S 299 8.83 1623K 21FLSWFDFLO 37 72 0 10/3/2000 1510 0.50 299 5.97 1623K 21FLPOLKP.C. CANAL9 10/ 5/2000 1000 0.50 299 0.47 1623K 21FLSWFDFLO 37 72 0 10/17/2000 1530 S 299 9.34 1623K 21FLSWFDFLO 37 72 0 11/1/2000 1120 S 299 9.17 1623K 21FLSWFDFLO 37 72 0 11/6/2000 1430 0.50 299 5.49 1623K 21FLSWFDFLO 37 72 0 12/6/2000 1330 0.50 299 3.18 1623K 21FLPOLKP.C. CANAL9 1/9/2001 1245 0.20 299 9.99 1623K 21FLSWFDFLO 37 72 0 2/7/2001 1545 0.55 299 15.56 1623K 21FLPOLKP.C. CANAL9 3/6/2001 1100 0.30 299 5.70 1623K 21FLSWFDFLO 37 72 0 3/7/2001 945 0.50 299 4.27 1623K 21FLSWFDFLO 37 72 0 4/3/2001 1015 0.50 299 1.45 1623K 21FLSWFDFLO 37 72 0 5/9/2001 1040 0.50 299 2.12 1623K 21FLSWFDFLO 37 72 0 6/5/2001 940 0.32 299 0.31 1623K 21FLSWFDFLO 37 72 0 8/9/2001 1330 0.50 299 3.97 1623K 21FLSWFDFLO 37 72 0 9/4/2001 1050 0.50 299 4.87 1623K 21FLSWFDFLO 37 72 0 10/2/2001 1050 0.50 299 9.60 1623K 21FLPOLKP.C. CANAL9 10/ 29/2001 1330 0.50 299 9.01 1623K 21FLSWFDFLO 37 72 0 1/8/2002 1035 0.50 299 1.45 1623K 21FLPOLKP.C. CANAL9 1/ 15/2002 1145 0.33 299 6.55 1623K 21FLSWFDFLO 37 72 0 2/6/2002 915 0.50 299 0.49 1623K 21FLSWFDFLO 37 72 0 3/4/2002 1110 0.50 299 3.87 1623K 21FLSWFDFLO 37 72 0 4/2/2002 1115 0.50 299 0.88 1623K 21FLPOLKP.C. CANAL9 4/ 17/2002 1055 0.15 299 4.30 1623K 21FLSWFDFLO 37 72 0 5/6/2002 1050 0.50 299 0.72 1623K 21FLSWFDFLO 37 72 0 7/4/2002 1530 0.50 299 7.30 1623K 21FLPOLKP.C. CANAL9 7/ 24/2002 930 0.50 299 2.78 1623K 21FLSWFDFLO 37 72 0 9/5/2002 1700 0.50 299 7.60 1623K 21FLSWFDFLO 37 72 0 10/1/2002 1200 0.50 299 6.45DRAFT DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek, November, 2005



## 105 WBID Station Date Time Depth Storet Code DO (mg/L) R-Code 1623K 21FLPOLKP.C. CANAL9 10/ 23/2002 930 0.30 299 2.42 1623K 21FLSWFDFLO 37 72 0 11/4/2002 1040 0.50 299 0.52 1623K 21FLSWFDFLO 37 72 0 12/4/2002 1050 0.50 299 11.16 1623K 21FLPOLKP.C. CANAL9 1/ 28/2003 1005 0.50 299 9.52 1623K 21FLTPA 27552158149358 2/5/2003 1345 0.20 299 7.65 1623K 21FLPOLKP.C. CANAL9 4/ 16/2003 930 0.50 299 2.22 1623K 21FLTPA 27552158149358 4/22/2003 1000 0.20 299 2.31 1623K 21FLPOLKP.C. CANAL9 7/ 23/2003 915 0.50 299 0.84 1623K 21FLTPA 27552158149358 8/19/2003 950 0.20 299 2.82 1623K 21FLPOLKP.C. CANAL9 10/ 8/2003 1020 0.50 299 5.54 1623K 21FLTPA 27552158149358 11/4/2003 1145 0.20 299 8.85 1623K 21FLPOLKP.C. CANAL9 1/7/2004 940 0.40 299 7.69 1623K 21FLPOLKP.C. CANAL9 4/ 15/2004 955 0.25 299 7.38Draft DO and Nutrient TM DL Repo rt for Lake Han c o c k and L o wer Saddle Cre e k – Appendix C



## APPENDIX C: TSI for PC, Backgrou nd, TMDL Target, and TSI-Unit Percent Reduction

Bana na Lak e TSI for Measured, PC, Backgro und, TMDL Ta rge t , TMDL, and

TSI-unit Per cent Redu cti on Bas e d on Backg round L50-IL7 5

Year Colo r (PCU) M e a s u r e d C a l i b rated Backgroun d IL75 Targ et IL75+5 TMDL Percent Red u ctio n 1 9 9 4 3 4

. 2 3 8 3 8 3 7 3

. 9 7 8

. 9 7 8

. 9 3 4 1 9 9 5 4 8

. 9 3 7 4

. 1 7 4

. 2 5 7

. 5 6 2

. 5 6 2

. 3 6 0

. 5 1 9 9 6 3 9

. 6 4 7 9

. 9 8 0 5 7

. 4 6 2

. 4 6 2

. 3 8 0

. 3 1 9 9 7 3 5

. 7 1 8 1

. 9 8 1

. 9 4 8

. 4 5 3

. 4 5 3

. 5 8 9

. 1 1 9 9 8 5 2

. 6 2 8 2 8 2 5 1

. 2 5 6

. 2 5 6

. 2 8 7

. 7 1 9 9 9 3 3

. 5 8 2

. 4 8 2

. 4 5 3

. 3 5 8

. 3 5 8

. 3 8 8

. 5 2 0 0 0 9 0

. 8 9 0

. 8 6 6

. 2 7 1

. 2 7 1

. 2 8 8

. 7 2 0 0 1 9 1

. 8 9 1

. 8 6 6

. 1 7 1

. 1 7 1

. 1 8 9

. 9 2 0 0 2 4 2 8 7

. 2 8 7

. 2 5 6

. 3 6 1

. 3 6 1

. 2 9 0

. 4 2 0 0 3 5 0 7 7

. 4 7 7

. 3 4 7

. 8 5 2

. 8 5 2

. 9 8 6

. 8 M i n i m u m 3 3

. 5 7 4

. 1 7 4

. 2 4 7

. 8 5 2

. 8 5 2

. 9 3 4 M a x i m u m 5 2

. 6 9 1

. 8 9 1

. 8 7 3

. 9 7 8

. 9 7 8

. 9 9 0

. 4

M e a n 4 2

. 1 8 3

. 1 8 3

. 1 5 7

. 8 6 2

. 8 6 2

. 8 7 9

. 6

Lake Bentle y TSI for Measured, PC, Backgro und, TMDL Ta rge t , TMDL, and TN and TP M ass Perc ent Redu ction

Y e a r M e a s u r e d Calib rated Backgroun d IL75 Targ et IL75+5 TMDL TN Ma ss Percent Red u ctio n TP Mass Percent Red u ctio n 1 9 9 4 * 7 1

. 7 4 9

. 3 5 4

. 3 5 4

. 5 8 4 6 9 1 9 9 5 * 7 0

. 8 4 8

. 9 5 3

. 9 5 4 8 3 8 1 1 9 9 6 7 9

. 2 7 9

. 2 6 5

. 6 7 0

. 6 7 0

. 6 6 8 6 8 1 9 9 7 7 4

. 2 7 5

. 2 4 1

. 2 4 6

. 2 4 6

. 8 9 3 9 3 1 9 9 8 7 5

. 3 7 5

. 2 4 2

. 5 4 7

. 5 4 7

. 6 9 2

. 3 9 2

. 3 1 9 9 9 7 4

. 8 7 4

. 8 4 2

. 9 4 7

. 9 4 7

. 8 9 0 9 0 2 0 0 0 7 2

. 2 7 6

. 8 5 1

. 8 5 6

. 8 5 6

. 6 8 4

. 9 8 4

. 4 2 0 0 1 7 1

. 7 7 5

. 5 4 5

. 7 5 0

. 7 5 0

. 8 9 0

. 7 9 0

. 7 2 0 0 2 * 7 2

. 6 7 3

. 6 4 3

. 5 4 8

. 5 4 7

. 5 9 5 9 4 2 0 0 3 6 7

. 3 7 1

. 3 4 0

. 5 4 5

. 5 4 6

. 2 8 9 8 9 M i n i m u m 6 7

. 3 7 0

. 8 4 0

. 5 4 5

. 5 4 6

. 2 6 8 6 8 M a x i m u m 7 9

. 2 7 9

. 2 6 5

. 6 7 0

. 6 7 0

. 6 9 5 9 4

M e a n 7 3

. 4 7 4

. 4 4 7

. 2 5 2

. 2 5 2

. 2 8 7 8 5

. 1 * Reductions in TP limited by back g round concent r a tions.

1Draft DO and Nutrient TM DL Repo rt for Lake Han c o c k and L o wer Saddle Cre e k – Appendix C

Lake Bonn y TSI for Measured, PC, Backgro und, TMDL Ta rge t , TMDL, and

TSI-unit Per cent Redu cti on Bas e d on Backg round L50-IL7 5

Y e a r M e a s u r e d P C Backgroun d IL75 Targ et IL75+5 TMDL Percent Red u ctio n 1 9 9 4 6 6

. 4 6 6

. 2 5 3

. 3 5 8

. 3 5 8

. 3 5 4

. 5 1 9 9 5 6 9

. 0 6 8

. 9 5 4

. 7 5 9

. 7 5 9

. 5 5 4

. 5 1 9 9 6 6 9

. 9 7 0

. 0 6 2

. 4 6 7

. 4 6 7

. 6 2 5

. 0 1 9 9 7 7 3

. 7 7 3

. 7 5 3

. 4 5 8

. 4 5 8

. 2 7 7

. 0 1 9 9 8 7 2

. 3 7 2

. 2 5 6

. 4 6 1

. 4 6 1

. 3 6 9

. 0 1 9 9 9 7 6

. 0 7 6

. 0 6 2

. 2 6 7

. 2 6 7

. 0 6 6

. 0 2000* 8 6

. 3 8 6

. 3 8 2

. 1 8 4

. 2 8 4

. 1 2 8

. 0 2 0 0 1 8 7

. 8 8 7

. 8 7 4

. 8 7 9

. 8 7 9

. 7 6 8

. 0 2 0 0 2 7 4

. 2 7 4

. 2 5 8

. 3 6 3

. 3 6 3

. 1 7 2

. 0 2 0 0 3 6 7

. 0 6 6

. 9 5 2

. 2 5 7

. 2 5 7

. 1 6 3

. 0 M i n i m u m 6 6

. 4 6 6

. 2 5 2

. 2 5 7

. 2 5 7

. 1 2 5

. 0 M a x i m u m 8 7

. 8 8 7

. 8 8 2

. 1 8 7

. 1 8 4

. 1 7 7

. 0 A v e r a g e 7 4

. 3 7 4

. 2 6 1

. 0 6 6

. 0 6 5

. 6 5 7

. 7 * T a rget for year 200 0 w a s set at half the diffe renc e betw e e n IL75 a nd PC due to a dry ye ar in the backgr oun d con d itio n.

Lake Crago TSI for Measured, PC, Backgro und, TMDL Ta rge t , TMDL, and

TSI-unit Per cent Redu cti on Bas e d on Backg round L50-IL7 5

Y e a r M e a s u r e d P C Backgroun d IL75 Targ et I L 7 5 + 5 T M D L Percent Red u ctio n 1 9 9 4 5 9

. 2 5 1

. 9 5 6

. 9 5 6

. 5 1 0 1 9 9 5 5 9

. 6 4 4

. 5 4 9

. 5 4 9

. 1 2 0 1 9 9 6 7 3

. 3 7 3

. 3 5 7

. 4 6 2

. 4 6 2

. 1 8 0 1 9 9 7 7 1

. 6 7 1

. 5 4 7

. 8 5 2

. 8 5 2

. 7 8 5 1 9 9 8 6 6

. 3 6 6

. 3 4 4

. 9 4 9

. 9 4 9

. 7 8 0 1 9 9 9 7 3

. 5 7 3

. 5 5 1

. 7 5 6

. 7 5 6

. 8 8 5 2 0 0 0 7 4

. 3 7 4

. 3 5 7

. 1 6 2

. 1 6 2

. 9 9 0 2 0 0 1 6 4

. 4 6 4

. 3 5 1

. 4 5 6

. 4 5 6

. 5 5 8 2 0 0 2 7 2

. 8 7 2

. 8 4 7 5 2 5 2

. 1 9 1

. 5 2 0 0 3 7 1

. 9 7 0

. 9 5 1

. 9 5 6

. 9 5 7 6 5 M i n i m u m 6 4

. 4 5 9

. 2 4 4

. 5 4 9

. 5 4 9

. 1 1 0 M a x i m u m 7 4

. 3 7 4

. 3 5 7

. 4 6 2

. 4 6 2

. 9 9 1

. 5 A v e r a g e 7 1 6 8

. 6 5 0

. 6 5 5

. 6 5 5

. 5 6 6

. 5

2Draft DO and Nutrient TM DL Repo rt for Lake Han c o c k and L o wer Saddle Cre e k – Appendix C

Eagle Lake TSI for Measured, PC, Backgro und, TMDL Ta rge t , TMDL, and TSI-unit Per cent Redu ction Based on Bac k ground L 5 0

- IL75

Year Existing Measured Calibrated Backgroun d IL75 Targ et IL75+5 TMDL Percent Red u ctio n 1 9 9 4 5 5

. 3 5 8

. 6 4 5

. 4 6 5 0

. 4 6 4 7

. 8 7 7 0 1 9 9 5 5 3

. 1 5 7

. 2 4 6

. 5 5 1

. 5 4 6

. 4 9 7 0 1 9 9 6 5 5 6 0

. 7 5 9

. 8 8 6 4

. 8 8 5 1

. 0 5 7 0 1 9 9 7 5 0

. 9 5 6

. 7 4 1

. 4 2 4 6

. 4 2 4 5

. 4 8 7 0 1 9 9 8 5 6

. 8 5 9

. 3 4 8

. 9 5 5 3

. 9 5 4 8

. 8 1 7 0 1 9 9 9 4 6

. 8 6 1

. 9 5 2

. 5 7 5 7

. 5 7 5 3

. 6 2 7 0 2 0 0 0 5 0

. 3 6 6

. 9 5 6

. 6 4 6 1

. 6 4 5 9

. 3 7 7 0 2 0 0 1 5 0

. 8 6 4 5 6

. 7 1 6 1

. 7 1 5 5

. 2 2 7 0 2 0 0 2 4 9

. 6 5 6

. 3 4 1

. 7 4 4 6

. 7 4 4 4

. 8 3 7 0 2 0 0 3 5 7

. 4 4 9

. 4 6 5 4

. 4 6 4 6

. 6 3 7 0 M i n i m u m 4 6

. 8 5 6

. 3 4 4 1

. 4 2 4 6

. 4 2 4 4

. 8 3 7 0 M a x i m u m 5 6

. 8 6 6

. 9 1 5 9

. 8 8 6 4

. 8 8 5 9

. 3 7 7 0

M e a n 5 2

. 1 5 9

. 9 1 4 9

. 9 3 5 4

. 9 3 4 9

. 9 4 7 0

Lake Gibs on TSI for Measured, PC, Backgro und, TMDL Ta rge t , TMDL, and

TSI-unit Per cent Redu cti on Bas e d on Backg round L50-IL7 5

Y e a r M e a s u r e d P C Backgroun d IL75 Targ et I L 7 5 + 5 T M D L Percent Red u ctio n 1 9 9 4 4 3

. 6 5 6

. 4 4 7

. 6 5 2

. 6 5 2

. 5 2 8 1 9 9 5 6 3

. 2 6 4

. 1 4 4

. 9 4 9

. 9 4 9

. 3 6 8 1 9 9 6 6 6

. 4 6 8

. 5 6 3 6 8 6 7

. 4 9 1 9 9 7 4 4

. 8 5 7

. 8 3 4

. 4 3 9

. 4 3 9

. 1 7 4 1 9 9 8 5 3

. 4 5 7

. 2 3 5

. 6 4 0

. 6 3 9

. 9 7 2 1 9 9 9 5 5

. 8 5 9 4 1

. 4 4 6

. 4 4 6

. 6 6 5 2000* 4 4

. 9 6 0

. 6 6 1

. 7 6 6

. 7 6 0

. 6 2 0 0 1 5 6

. 5 6 3

. 6 5 1

. 1 5 6

. 1 5 5

. 4 5 5 2 0 0 2 5 6

. 3 6 0

. 5 4 3 4 8 4 7

. 7 6 0 2 0 0 3 5 3 6 0

. 8 3 9 4 4 4 2

. 8 7 7 M i n i m u m 4 3

. 6 5 6

. 4 3 4

. 4 3 9

. 4 3 9

. 1 9 M a x i m u m 6 6

. 4 6 8

. 5 6 3 6 8 6 7

. 4 7 7 A v e r a g e 5 3

. 8 6 0

. 8 4 6

. 2 5 1

. 2 5 0

. 1 5 6

. 4 * Year 20 00 n o t includ ed as th e lake i n the ba ckgrou nd co ndi tion ha d hi gher concentrati ons than the curre nt conditi on.

3Draft DO and Nutrient TM DL Repo rt for Lake Han c o c k and L o wer Saddle Cre e k – Appendix C

Lake Hollings w o r t h TSI for Measured, PC, Backgro und, TMDL Ta rge t , TMDL, and TN and TP M ass Perc ent Redu ction

Y e a r M e a s u r e d Calib rated Backgroun d IL75 Targ et IL75+5 TMDL TN Ma ss Percent Red u ctio n TP Mass Percent Red u ctio n 1 9 9 4 * 8 8

. 4 8 8

. 3 5 7

. 7 6 2

. 7 6 2

. 8 9 2

. 2 8 8 1 9 9 5 * 9 0

. 8 9 0

. 9 6 1

. 4 6 6

. 4 6 6

. 3 9 3 8 3 1 9 9 6 8 9

. 6 8 9

. 6 7 8

. 8 8 3

. 8 8 3

. 8 5 0 5 0 1 9 9 7 * 8 9

. 1 8 9

. 1 5 2

. 9 5 7

. 9 5 7

. 8 9 3

. 2 8 9 1 9 9 8 * 8 2

. 7 8 2

. 7 5 2 5 7 5 6

. 4 9 0 8 5 1 9 9 9 * 8 4

. 5 8 4

. 6 5 4

. 2 5 9

. 2 5 8

. 9 9 0 8 7 2000* * 8 6

. 4 8 8

. 6 8 1

. 7 8 4

. 1 8 3

. 9 4 0

. 5 3 7 2 0 0 1 8 7

. 1 8 7 5 8

. 8 6 3

. 8 6 3

. 8 8 8 8 8 2 0 0 2 * 7 2

. 6 7 2

. 6 4 7

. 9 5 2

. 9 5 2

. 8 8 2

. 5 7 5 2 0 0 3 * 7 0

. 3 7 3

. 3 4 4

. 5 4 9

. 5 4 9

. 1 8 4 8 2 M i n i m u m 7 0

. 3 7 2

. 6 4 4

. 5 4 9

. 5 4 9

. 1 4 0

. 5 3 7 M a x i m u m 9 0

. 8 9 0

. 9 8 1

. 7 8 4

. 1 8 3

. 9 9 3

. 2 8 9

M e a n 8 4

. 2 8 4

. 7 5 9 6 3

. 7 6 3

. 6 8 0

. 3 7 6

. 4 * Reductions in TP limit ed b y bac kground concent rations. ** Used 1/2 of th e difference bet ween PC and Bac k ground as ta rg e t for TM DL due t o background co ncentrations gre a ter than e x isting.

Lake Le na TSI for PC, Bac k grou nd, TMDL Targ e t , TM DL, and TSI-unit red u ction Base d on Bac k gr ound L50

- IL 75

Y e a r P C Backgroun d IL75 Targ et I L 7 5 + 5 T M D L Percent Red u ctio n 1 9 9 4 7 2

. 5 6 0

. 2 8 6 5

. 2 8 6 5

. 0 6 5 1 1 9 9 5 6 6

. 3 1 5 7

. 8 4 6 2

. 8 4 6 2

. 1 4 3 5 1 9 9 6 6 6

. 6 9 5 7

. 7 6 6 2

. 7 6 6 2

. 4 3 3 5 1 9 9 7 6 4

. 8 4 5 5

. 8 1 6 0

. 8 1 6 0

. 2 5 3 7 1 9 9 8 6 4

. 0 7 5 6

. 0 7 6 1

. 0 7 6 1

. 0 6 2 6 1 9 9 9 6 9

. 3 5 8

. 1 4 6 3

. 1 4 6 3

. 1 3 5 2 2 0 0 0 7 6

. 2 4 6 7

. 1 1 7 2

. 1 1 7 2

. 1 4 2 2 0 0 1 7 4

. 4 9 6 4

. 2 7 6 9

. 2 7 6 9

. 2 9 4 5 2 0 0 2 7 3

. 7 5 6 3

. 8 5 6 8

. 8 5 6 8

. 6 1 3 8 2 0 0 3 7 1

. 9 9 5 8

. 9 3 6 3

. 9 3 6 3

. 9 1 4 9

. 5 M i n i m u m 6 4

. 0 7 5 5

. 8 1 6 0

. 8 1 6 0

. 2 5 2 6 M a x i m u m 7 6

. 2 4 6 7

. 1 1 7 2

. 1 1 7 2

. 1 5 2 A v e r a g e 7 0

. 0 2 6 0

. 0 1 6 5

. 0 1 6 4

. 8 4 1

. 1

4Draft DO and Nutrient TM DL Repo rt for Lake Han c o c k and L o wer Saddle Cre e k – Appendix C

Lake Park er TSI for Measured, PC, Backgro und, TMDL Ta rge t , TMDL, and

TSI-unit Per cent Redu cti on Bas e d on Backg round L50-IL7 5

Year PCU Colo r M e a s u r e d P C Backgroun d IL75 Targ et IL75+5 TMDL Percent Red u ctio n 1 9 9 4 2 3

. 5 7 8

. 8 78.7 6 5

. 1 7 0

. 1 6 9

. 9 6 1 1 9 9 5 2 5 7 4

. 9 7 5 5 7

. 1 6 2

. 1 6 2 6 7

. 5 1 9 9 6 2 7

. 4 7 8

. 7 78.7 7 0

. 5 7 5

. 5 7 5

. 5 2 8 1 9 9 7 4 8

. 6 8 3

. 1 83.1 6 1

. 3 6 6

. 3 6 6

. 2 7 8

. 5 1 9 9 8 8 2 8 1

. 5 81.5 6 1

. 2 6 6

. 2 6 6 7 6

. 8 1 9 9 9 3 2 8 6 8 6 7 4

. 3 7 9

. 3 7 9

. 4 5 4

. 6 2000* 3 2 9 0

. 7 90.7 8 9

. 8 8 9

. 8 8 9

. 8 1 0 2 0 0 1 5 5

. 3 8 7

. 8 87.8 7 6

. 2 8 1

. 2 8 1

. 1 5 8 2 0 0 2 3 4 8 4

. 3 84.3 6 7

. 1 7 2

. 1 7 1

. 9 7 5

. 1 2 0 0 3 5 3

. 8 7 7

. 4 77.4 6 1

. 3 6 6

. 3 6 6

. 3 6 6

. 2 Minimum 23.5 7 4

. 9 7 5 5 7

. 1 6 2

. 1 6 2 1 0 Maximum 82 9 0

. 7 9 0

. 7 8 9

. 8 8 9

. 9 8 9

. 8 7 8

. 5 Average 38.2 8 2

. 3 8 2

. 3 6 8

. 4 7 2

. 9 7 2

. 8 5 7

. 6 * Used n a tural lan d use (IL7 5) as T M DL target becaus e bac kgrou nd pl us 5 T S I units w a s greater than the e x istin g cond itio n (measur ed co nditi on).

Spirit Lake TSI for Measured, PC, Backgro und, TMDL Ta rge t , TMDL, and TSI-unit Per cent Redu ction Based on Bac k ground L 5 0

- IL75

Year Existing Measured Calibrated Backgroun d IL75 Targ et IL75+5 TMDL Percent Red u ctio n 1 9 9 4 7 5

. 9 7 0

. 4 2 7 5

. 4 2 7 0

. 1 8 5 5 1 9 9 5 7 1 6 9

. 1 6 7 4

. 1 6 6 4

. 7 6 5 5 1 9 9 6 7 6

. 4 7 0

. 1 3 7 5

. 1 3 7 1

. 2 1 5 5 1 9 9 7 5 1

. 3 6 1

. 1 5 0

. 3 6 5 5

. 3 6 5 4

. 2 5 5 1 9 9 8 5 6

. 6 6 6

. 5 5 9

. 6 2 6 4

. 6 2 6 0

. 0 4 5 5 1 9 9 9 4 8

. 5 6 7

. 3 6 0

. 7 1 6 5

. 7 1 6 2

. 0 6 5 5 2 0 0 0 5 3

. 7 7 0

. 1 6 4

. 1 5 6 9

. 1 5 6 4

. 7 5 5 2 0 0 1 5 1

. 8 6 9

. 9 6 2

. 7 6 7

. 7 6 4

. 5 6 5 5 2 0 0 2 5 1

. 3 6 4

. 4 5 3

. 7 5 8

. 7 5 7

. 2 1 5 5 2 0 0 3 5 1

. 2 6 3

. 7 6 2

. 2 2 6 7

. 2 2 5 7

. 2 6 5 5 M i n i m u m 4 8

. 5 6 1

. 1 1 5 0

. 3 6 5 5

. 3 6 5 4

. 2 5 5 M a x i m u m 5 6

. 6 7 6

. 3 8 7 0

. 4 2 7 5

. 4 2 7 1

. 2 1 5 5

M e a n 5 2

. 1 6 8

. 6 3 6 2

. 3 2 6 7

. 3 2 6 2

. 6 2 5 5

5Draft DO and Nutrient TM DL Repo rt for Lake Han c o c k and L o wer Saddle Cre e k – Appendix D

1 

## Appendix D: Lake Hancock Basin Modeled Lakes Mass for TN and TP for Calibrated Model, TMDL, and Percent Reduction

Banana Lake Mass for TN and TP for Calibrated Model and TMDL, with Mass Percent Reductions (kg/year)

Year TN-MASS Calibrated TN-MASS TMDL TN-MASS % Reduction TP-MASS Calibrated TP-MASS TMDL TP-MASS % Reduction 1994 78,712.1 50,039.7 36.4 141,282.7 93,190.9 34.0 1995 45,448.0 17,227.0 62.1 135,638.2 53,593.0 60.5 1996 42,615.2 9,373.2 78.0 97,385.7 19,276.7 80.2 1997 94,168.5 11,160.9 88.1 111,217.9 12,286.5 89.0 1998 81,718.7 10,616.6 87.0 125,292.0 15,516.4 87.6 1999 53,454.0 6,283.2 88.2 75,148.4 8,672.1 88.5 2000 88,872.9 10,175.7 88.6 104,952.1 11,886.2 88.7 2001 152,977.7 15,734.1 89.7 139,287.0 14,120.9 89.9 2002 147,416.3 15,170.1 89.7 139,618.9 13,504.6 90.3 2003 83,547.1 11,665.8 86.0 106,314.2 14,231.5 86.6 Minimum 42,615.2 6,283.2 36.4 75,148.4 8,672.1 34.0 Maximum 152,977.7 50,039.7 89.7 141,282.7 93,190.9 90.3

Mean 86,893.0 15,744.6 79.4 117,613.7 25,627.9 79.5

Lake Bentley Mass for TN and TP for Calibrated Model and TMDL, with Mass Percent Reductions (kg/year)

Year TN-MASS Calibrated TNMASS TMDL TN-MASS % Reduction TP-MASS Calibrated TPMASS TMDL TP-MASS % Reduction 1994* 11718.3 2110.6 82 777.6 231.5 70.2 1995* 14857.2 2598.2 82.5 658 204.8 68.9 1996 8935.3 3549.6 60.3 1678.7 582.3 65.3 1997 19613 2426 87.6 3979.1 492.8 87.6 1998 13588.2 1720.5 87.3 4592 449.1 90.2 1999 4153.5 478.6 88.5 1728.4 182.7 89.4 2000 3372.5 526.1 84.4 1443.4 225.2 84.4 2001 5950.3 784.1 86.8 2480.2 270.7 89.1 2002* 10424.6 1940.8 81.4 3293.5 298.5 90.9 2003 9710.4 1662.8 82.9 8596.9 1027.5 88 Minimum 3372.5 478.6 60.3 658 182.7 65.3 Maximum 19613 3549.6 88.5 8596.9 1027.5 90.9

Mean 10232.3 1779.7 82.4 2922.8 396.5 82.4 * Reductions in TP limited by background concentrations.Draft DO and Nutrient TM DL Repo rt for Lake Han c o c k and L o wer Saddle Cre e k – Appendix D

2 Lake Bonny Mass for TN and TP for Calibrated Model and TMDL, with Mass Percent Reductions (kg/year)

Year TN-MASS Calibrated TN-MASS TMDL TN-MASS % Reduction TP-MASS Calibrated TP-MASS TMDL TP-MASS % Reduction 1994 10,059.0 4,576.8 54.5 719.2 327.2 54.5 1995 9,062.8 4,123.6 54. 5 1,605.6 730.5 54.5 1996 10,031.4 7,523.5 25. 0 1,241.1 930.8 25.0 1997 20,827.0 4,790.2 77.0 6,615.3 1,521.5 77.0 1998 15,320.9 4,749.5 69. 0 1,706.9 529.1 69.0 1999 11,479.9 3,903.2 66. 0 1,568.9 533.4 66.0 2000* 17,405.3 12,531.7 28.0 2,030.3 1,461.8 28.0 2001 29,067.4 9,301.6 68.0 4,604.5 1,473.4 68.0 2002 35,883.1 10,047.3 72. 0 2,597.4 727.3 72.0 2003 11,699.1 4,328.5 63. 0 1,287.9 476.5 63.0 Minimum 9,062.8 3,903. 2 25.0 719.2 327.2 25.0 Maximum 35,883.1 12,531.7 77.0 6,615.3 1,521.5 77.0 Average 17,083.6 6,587.6 57.7 2,397.7 871.2 57.7 * Target for year 2000 was set at half the difference between IL75 and PC due to a dry year in the background condition.

Lake Crago Mass for TN and TP for Calibrated Model and TMDL, with Mass Percent Reductions (kg/year)

Year TN-MASS Calibrated TNMASS TMDL TN-MASS % Reduction TP-MASS Calibrated TPMASS TMDL TP-MASS % Reduction 1994 6,181.7 5,114.2 17.3 1,191.9 1,015.4 14.8 1995 6,354.0 3,162.7 50. 2 1,033.6 601.8 41.8 1996 16,026.3 5,648.0 64.8 5,224.1 1,342.3 74.3 1997 17,612.7 4,329.9 75.4 11,090.6 2,146.9 80.6 1998 8,963.0 2,879.1 67.9 4,267.7 1,074.6 74.8 1999 12,199.9 2,846.4 76. 7 3,875.0 749.3 80.7 2000 8,841.5 2,741.4 69. 0 2,955.7 484.7 83.6 2001 4,945.7 2,698.4 45.4 4,521.1 1,952.9 56.8 2002 19,639.6 4,233.6 78. 4 4,385.2 693.6 84.2 2003 9,748.1 3,460.9 64. 5 2,444.3 887.3 63.7 Minimum 4,945.7 2,698.4 17.3 1,033.6 484.7 14.8 Maximum 19,639.6 5,648.0 78.4 11,090.6 2,146.9 84.2 Average 11,051.3 3,711.5 61. 0 4,098.9 1,094.9 65.5Draft DO and Nutrient TM DL Repo rt for Lake Han c o c k and L o wer Saddle Cre e k – Appendix D

3 Eagle Lake Mass for TN and TP for Calibrated Model and TMDL, with Mass Percent Reductions (kg/year)

Year TN-MASS Calibrated TNMASS TMDL TN-MASS % Reduction TP-MASS Calibrated TPMASS TMDL TP-MASS % Reduction 1994 21,801.6 6,540.5 70 624.6 187.4 70 1995 22,129.8 6,639.0 70 647.2 194.2 70 1996 15,462.0 4,638.6 70 560.3 168.1 70 1997 28,597.2 8,579.2 70 811.8 243.5 70 1998 19,421.4 5,826.4 70 851.8 255.6 70 1999 15,395.9 4,618.8 70 510.2 153.1 70 2000 17,420.4 5,226.1 70 489.6 146.9 70 2001 21,855.3 6,556.6 70 543.6 163.1 70 2002 25,974.2 7,792.3 70 753.4 226 70 2003 19,534.5 5,860.3 70 613.5 184.1 70 Minimum 15,395.9 4,618.8 70 489.6 146.9 70 Maximum 28,597.2 8,579.2 70 851.8 255.6 70

Mean 20,759.2 6,227.8 70 640.6 192.2 70

Lake Gibson Mass for TN and TP for Calibrated Model and TMDL, with Mass Percent Reductions (kg/year)

Year TN-MASS Calibrated TNMASS TMDL TN-MASS % Reduction TP-MASS Calibrated TPMASS TMDL TP-MASS % Reduction 1994 10,815.4 7,787.1 28 5,622.7 4,048.3 28 1995 13,422.2 4,295.1 68 4,428.9 1,417.3 68 1996 8,323.0 7,573.9 9 1,948.3 1,772.9 9 1997 16,079.5 4,180.7 74 10,354.5 2,692.2 74 1998 12,176.4 3,409.4 72 4,401.6 1,232.5 72 1999 8,676.8 3,036.9 65 2,882.7 1,008.9 65 2000* 8,950.2 8,950.2 1,652.0 1,652.0 2001 10,787.6 4,854.4 55 1,197.1 538.7 55 2002 12,066.5 4,829.2 60 2,414.0 965.6 60 2003 13,944.7 3,207.3 77 2,248.5 517.5 77 Minimum 8,323.0 3,036.9 9 1,197.1 517.5 9 Maximum 16,079.5 8,950.2 77 10,354.5 4,048.3 77 Average 11,524.2 5,212.4 56. 4 3,715.0 1,584.6 56.4 *Year 2000 not included as the lake in the backgr ound condition had higher c oncentrations than the current condition.Draft DO and Nutrient TM DL Repo rt for Lake Han c o c k and L o wer Saddle Cre e k – Appendix D

4 Lake Hollingsworth Mass for TN and TP for Calibrated Model and TMDL, with Mass Percent Reductions (kg/year)

Year TN-MASS Calibrated TN-MASS TMDL TN-MASS % Reduction TP-MASS Calibrated TP-MASS TMDL TP-MASS % Reduction 1994* 52,471.0 4,092.7 92.2 7,376.5 885.2 88 1995* 59,081.4 4,135.7 93.0 4,380.1 744.6 83 1996 31,496.1 15,748.1 50. 0 2,581.2 1,290.6 50 1997* 49,304.1 3,352.5 93.2 6,633.2 729.7 89 1998* 28,281.7 2,828.2 90.0 3,286.4 493.2 85 1999* 16,565.5 1,656.6 90.0 2,505.4 325.6 87 2000** 9,500.9 5,653.1 40. 5 1,927.6 1,214.2 37 2001 16,898.6 2,196.6 87. 0 3,611.2 587.4 83.7 2002* 19,806.3 3,466.1 82.5 1,113.7 278.4 75 2003* 15,868.4 2,538.9 84.0 2,477.6 445.8 82 Minimum 9,500.9 1,656. 6 40.5 1,113.7 278.4 37 Maximum 59,081.4 15,748.1 93.2 7,376.5 1,290.6 89

Mean 29,927.4 4,566.8 80.2 3,589.3 699.5 76 * Reductions in TP limit ed by background concentrations. ** Used 1/2 of the difference between PC and Background as target for TMDL due to background concentrations greater than existing.

Lake Lena Mass for TN and TP for Calibrated Model and TMDL, with mass percent reductions (kg/year)

Year TN-MASS Calibrated TNMASS TMDL TN-MASS % Reduction TP-MASS Calibrated TPMASS TMDL TP-MASS % Reduction 1994 15225.1 7460.3 51 566.1 277.4 51 1995 19333.9 12567 35 776.6 504.8 35 1996 4681.8 3043.2 35 229.3 149 35 1997 15377.8 9688 37 732.4 461.4 37 1998 18579.7 13749 26 794.6 588 26 1999 1861 893.3 52 290 139.2 52 2000 2326.6 1349.4 42 270.7 157 42 2001 4203.1 2311.7 45 235 129.2 45 2002 22247.5 13793.5 38 374.8 232.4 38 2003 29676.6 14986.7 49.5 887.8 448.3 49.5 Minimum 1861 893.3 26 229.3 129.2 26 Maximum 29676.6 14986.7 52 887.8 588 52 Average 13351.3 7984.2 41 515.7 308.7 41Draft DO and Nutrient TM DL Repo rt for Lake Han c o c k and L o wer Saddle Cre e k – Appendix D

Lake Park er Mass for TN and TP for Calibrated Mo del and TMDL,

w i th Mas s Percen t Re du ctions (kg/y e ar)

Year TN-MASS Calibrated TNMASS TMDL TN-MASS % Red u ctio n TP-MASS Calibrated TPMASS TMDL TP-MASS % Red u ctio n 1 9 9 4 1 4 7
, 9 3 5

. 2 5 9
, 8 2 5

. 4 59. 6 1 6
, 3 1 4

. 2 6
, 6 2 8

. 2 5 9

. 4 1 9 9 5 1 0 3
, 1 1 9

. 6 3 4
, 6 3 5

. 3 66. 4 2 0
, 0 1 0

. 6 6
, 6 8 0

. 1 6 6

. 6 1 9 9 6 1 0 3
, 5 3 0

. 0 7 2
, 6 9 6

. 3 29. 8 1 2
, 2 7 0

. 2 8
, 5 7 8

. 1 3 0

. 1 1 9 9 7 2 2 4
, 4 6 1

. 3 4 9
, 8 3 9

. 9 77. 8 4 7
, 9 1 9

. 0 10,747.1 7 7

. 6 1 9 9 8 1 6 1
, 8 1 3

. 0 3 8
, 5 1 6

. 0 7 6

. 2 127,68 6

. 9 2 9
, 8 3 7

. 5 7 6

. 6 1 9 9 9 1 6 1
, 9 2 8

. 1 7 2
, 9 9 1

. 8 54. 9 1 6
, 1 5 4

. 1 7
, 2 8 9

. 3 5 4

. 9 2000* 116,17 7

. 3 1 0 3
, 2 2 0

. 2 11. 2 5 2
, 0 3 3

. 6 46,620.0 1 0

. 4 2 0 0 1 2 1 7
, 5 9 3

. 1 9 1
, 9 9 6

. 3 57. 7 2 5
, 2 5 0

. 8 10,750.2 5 7

. 4 2 0 0 2 4 1 6
, 9 3 5

. 2 104,88 2

. 1 74. 8 3 5
, 8 3 9

. 4 9
, 0 3 1

. 3 7 4

. 8 2 0 0 3 1 7 3
, 8 9 4

. 3 5 9
, 4 2 1

. 4 65. 8 5
, 7 6 8

. 9 2
, 0 9 6

. 3 6 3

. 7 M i n i m u m 1 0 3
, 1 1 9

. 6 3 4
, 6 3 5

. 3 1 1

. 2 5
, 7 6 8

. 9 2
, 0 9 6

. 3 1 0

. 4 M a x i m u m 4 1 6
, 9 3 5

. 2 104,88 2

. 1 7 7

. 8 1 2 7
, 6 8 6

. 9 46,620.0 7 7

. 6 A v e r a g e 1 8 2
, 7 3 8

. 7 6 8
, 8 0 2

. 5 5 7

. 4 3 5
, 9 2 4

. 8 13,825.8 5 7

. 1 * Used natural la nduse (IL75 ) as TMDL ta rget bec uase background plus 5 TSI units w a s g r eate r than the existing con d ition (measured condi tion).

Spirit Lake Mass for TN and TP for Calibrated Mo del and TMDL,

w i th Mas s Percen t Re du ctions (kg/y e ar)

Year TN-MASS Calibrated TNMASS TMDL TN-MASS % Red u ctio n TP-MASS Calibrated TPMASS TMDL TP-MASS % Red u ctio n 1 9 9 4 1 5 9

. 7 7 1

. 9 5 5 4
, 7 6 3

. 4 2
, 1 4 3

. 5 5 5 1 9 9 5 1 9 0

. 6 8 5

. 7 5 5 5
, 6 2 4

. 3 2
, 5 3 0

. 9 5 5 1 9 9 6 1 5 1

. 5 6 8

. 2 5 5 3
, 9 5 5

. 4 1
, 7 7 9

. 9 5 5 1 9 9 7 2 6 1

. 3 1 1 7

. 6 5 5 7
, 6 0 1

. 4 3
, 4 2 0

. 6 5 5 1 9 9 8 2 4 0

. 6 1 0 8

. 2 5 5 5
, 2 6 8

. 1 2
, 3 7 0

. 6 5 5 1 9 9 9 1 4 4 6 4

. 8 5 5 3
, 3 8 4

. 1 1
, 5 2 2

. 9 5 5 2 0 0 0 1 2 0

. 6 5 4

. 3 5 5 3
, 0 8 6

. 9 1
, 3 8 9

. 1 5 5 2 0 0 1 1 2 7

. 7 5 7

. 5 5 5 4
, 0 7 0

. 3 1
, 8 3 1

. 7 5 5 2 0 0 2 2 6 5

. 3 1 1 9

. 4 5 5 7
, 6 0 8

. 7 3
, 4 2 3

. 9 5 5 2 0 0 3 2 3 2 1 0 4

. 4 5 5 5
, 7 9 0

. 5 2
, 6 0 5

. 7 5 5 M i n i m u m 1 2 0

. 6 5 4

. 3 5 5 3
, 0 8 6

. 9 1
, 3 8 9

. 1 5 5 M a x i m u m 2 6 5

. 3 1 1 9

. 4 5 5 7
, 6 0 8

. 7 3
, 4 2 3

. 9 5 5

M e a n 1 8 9

. 3 8 5

. 2 5 5 5
, 1 1 5

. 3 2
, 3 0 1

. 9 5 5

5Draft DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek – Appendix E1Appendix E:Lake Hancock Basin Modeled Lakes AnnualAverage Concentrations for TN, TP,and ChlorophyllaBanana Lake Annual Average Concentrations for TN, TP, and Chlorophylla(μg/L)YearMeasuredTNCalibratedTNTMDLTNBackgroundTNMeasuredTPCalibratedTPTMDLTPBackgroundTPMeasuredChlaCalibratedChlaTMDLChlaBackgroundChla199425852584.819281443.3816.6816.9657.6189.9122.8122.7106.782.819951702.51703.8841.4660.6770.9770.6472.4158.666.366.73727199620652065.2726.1570.6762.4762.6324.7187.2111.1111.845.733.419972433.82433.3476.6385.9643.4643.1189.5115.5114.6114.725.117.119982411.32410.2534.6430.9717.3717.1231.3127.2118.2118.230.821.319992719.32719.7645.3512.9751.4751.3238.8152.5104.2104.631.222.220004334.54333.91149.5870.91051.21051337.5269.8167.5167.378.960.220014762.54761.61147864.5983984.2294.8219.5166.4165.978.460.120023355.83354.9656.8519.7736736.7205.2144147.5147.445.632.6200324382438.4574.8457.8657.5657219.8125.26160.717.512.1Minimum1702.51703.8476.6385.9643.4643.1189.5115.56160.717.512.1Maximum4762.54761.619281443.31051.21051657.6269.8167.5167.3106.782.8Mean2880.82880.6868671.7789789.1317.1168.911811849.736.9Draft DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek – Appendix E2Lake Bentley Annual Average Concentrations for TN, TP, and Chlorophylla(μg/L)YearMeasuredTNCalibratedTNTMDLTNBackgroundTNMeasuredTPCalibratedTPTMDLTPBackgroundTPMeasuredChlaCalibratedChlaTMDLChlaBackgroundChla1994*2136.8619.548411250.950.85018.113.81995*2347.7667.1443.494.943.142.846.117.711.7199624722472.51383.81111237.3237130.68479.679.352.740.4199721382373.3467.3367.6241241.564.453.947.547.110.26.719982186.72186.8467.2375.6293.3293.873.158.653.753.211.57.819992018.82018.7465.9383.2308308.387.155.856.856.611.88.120001553.82387.7729.5576.6369369.713411958.358.320.615.120011531.42187.6549.4437.7331.933194.872.455.255.514.19.82002*1437.31577.6408.5344.4221.1221.646.843.369.469.113.910.220031192.31740.8451.5357.1413413.4123.479.643.543.1106.4Minimum1192.31577.6408.5344.4221.194.943.142.843.543.1106.4Maximum24722472.51383.81111413413.413411979.679.352.740.4Mean1816.32143621488.1301.8262.384.8665855.81813* Reductions in TP limitedby background concentrations.Lake Bonny Annual Average Concentrations for TN, TP, and Chlorophylla(μg/L)YearMeasuredTNCalibratedTNTMDLTNMeasuredTPCalibratedTPTMDLTPMeasuredChlaCalibratedChlaTMDLChla19941,417.81,418.0869.982.582.951.938.735.723.819951,238.51,238.9754.7121.5121.477.747.737.829.419961,723.91,724.51,459.4137.3137.2117.140.045.635.719971,834.51,834.3729.4238.5238.1106.456.354.725.919981,692.51,692.7831.4125.3125.464.559.943.032.319992,331.32,331.41,244.8195.8195.3108.160.260.038.920004,471.34,470.83,744.1341.4341.8287.6111.886.4104.420014,053.84,053.82,145.7359.9360.6196.7141.586.1105.320022,542.52,542.01,197.6145.6145.470.353.253.630.820031,420.11,420.6767.7105.9105.559.535.737.920.1Note: Background values not provided.Draft DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek – Appendix E3Lake Crago Annual Average Concentrations for TN, TP, and Chlorophylla(μg/L)YearMeasuredTNCalibratedTNTMDLTNMeasuredTPCalibratedTPTMDLTPMeasuredChlaCalibratedChlaTMDLChla1994847.9726.997.087.423.520.51995880.8494.789.162.023.613.019962,010.32,009.9960.1256.3257.0117.346.446.529.519971,674.71,674.9537.3344.0345.1130.547.947.019.019981,168.71,168.9466.3212.8212.692.339.139.215.419991,910.01,909.8679.7240.0239.692.751.151.123.620001,972.51,971.5913.5250.7250.890.554.754.430.320011,092.01,092.7697.7272.0272.8171.233.232.821.620021,784.01,784.6514.8199.6199.760.051.351.218.520031,279.31,279.7565.8155.6156.083.374.564.931.7Note: Background values not provided.Eagle Lake Annual Average Concentrations for TN, TP, and Chlorophylla(μg/L)YearMeasuredTNCalibratedTNTMDLTNBackgroundTNMeasuredTPCalibratedTPTMDLTPBackgroundTPMeasuredChlaCalibratedChlaTMDLChlaBackgroundChla19941,091.51,559.2798.7465.642.355.828.137.515.315.88.87.61995858.71,487.7761.8509.548.553.827.141.412.213.97.77.71996838.31,860.0967.21,279.327.876.739.697.114.715.39.615.21997749.31,379.9698.8381.228.148.324301414.57.75.71998878.01,367.5698.7536.561.561.731.543.517.317.810.210.21999517.03,180.91,688.71,100.133.8126.566.787.49.19.16.76.52000640.04,188.22,294.01,296.119.5154.884.8100.813.613.210.39.42001688.33,261.21,724.11,267.720.7111.157.995.913.31399.92002691.01,386.5696.5403.718.34924.131.613.713.775.62003670.01,403.5717.4587.823.852.826.645.7158.39.9Minimum517.01,367.5696.5381.218.348.324309.19.16.75.6Maximum1,091.54,188.22,294.01,296.161.5154.884.8100.817.317.810.315.2Mean762.22,107.51,104.6782.832.4794161.113.714.18.58.8Draft DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek – Appendix E4Lake Gibson Annual Average Concentrations for TN, TP, and Chlorophylla(μg/L)YearMeasuredTNCalibratedTNTMDLTNMeasuredTPCalibratedTPTMDLTPMeasuredChlaCalibratedChlaTMDLChla1994714.31,181.9949.9221.5222.1185.33.59.87.919951,196.71,302.2594.2188.0187.697.724.724.710.21996997.31,209.51,137.9146.5145.9138.350.750.447.61997666.41,274.9489.2266.3266.0125.24.610.63.31998900.11,249.3513.4190.8190.691.79.610.03.419991,123.91,486.0746.3213.8213.6118.69.710.04.92000*658.62,108.92,108.9215.1214.8214.84.87.47.42001823.31,686.41,013.8130.0130.081.217.017.410.72002712.51,065.4554.3118.5118.768.120.520.09.12003685.01,359.4487.6130.4130.353.213.813.74.1*Year 2000 not included as the lake in the background condition had higher concentrations than thecurrent condition. Background valuesNot provided.Lake Hollingsworth Annual Average Concentrations for TN, TP, and Chlorophylla(μg/L)YearMeasuredTNCalibratedTNTMDLTNBackgroundTNMeasuredTPCalibratedTPTMDLTPBackgroundTPMeasuredChlaCalibratedChlaTMDLChlaBackgroundChla1994*25854682.5897.6688.7816.6394116.1115122.8131.235.826.31995*1702.54655.2831.4648.8770.927496.189.366.3236.564.948.1199620654130.62745.31907.7762.4261.7176.6133.8111.1220.7168.1130.41997*2433.83802.5588.2468.6643.4313.982.981.6114.6195.333.623.91998*2411.32965.5616.3496.9717.322972.670.9118.2116.525.919.21999*2719.33626786.3621.2751.4329.599.296.3104.2103.925.418.82000**4334.54183.730622678.31051.2450.8349.7347.8167.5130107.396.520014762.53795977.5756.4983419.7147.5140.6166.4120.536.126.42002*3355.82171.2619.8430.6736110.44342.8147.556.415.810.32003*24382075565.8454.9657.5195.367.966.86144.410.77.7Minimum1702.52075565.8430.6643.4110.44342.86144.410.77.7Maximum4762.54682.530622678.31051.2450.8349.7347.8167.5236.5168.1130.4Mean2880.83608.71169915.2789297.8125.2118.5118135.652.440.8* Reductions in TP limitedby background concentrations.** Used 1/2 of the difference between PC and Background as targetfor TMDL due to background concentrations greater than existing.Draft DO and Nutrient TMDL Report for Lake Hancock and Lower Saddle Creek – Appendix E5Lake Parker Annual Average Concentrations for TN, TP, and Chlorophylla(μg/L)YearMeasuredTNCalibratedTNTMDLTNMeasuredTPCalibratedTPTMDLTPMeasuredChlaCalibratedChlaTMDLChla19942349.82350.31318.8175175.5103.39493.457.6199518151815.7872.6190190.4100.367.667.833.5199623162316.71865.8182.3182148.492.3927819972586.52586.8952.8275275.6116.6123.812352.8199824692468.9976.5532.3532.3244.3106.410649.5199936293629.52269.1256.5255.9163.8148.4148.7109.12000*4507.545074216.6709.9710.5671155.7155.5151.520014428.54428.82685.6337.3337.3210.7139.9139.9104.920023729.13729.71591.1233.4233.4104.6122.9122.166.320032584.52584.41314.394.494.849.4109.1108.656.3* Used natural land use (IL75) as TMDL target because backgroundplus 5 TSI units was greater than the existing condition (measured condition).Background values not provided.Spirit Lake Annual Average Concentrations for TN, TP, and Chlorophylla(μg/L)YearMeasuredTNCalibratedTNTMDLTNBackgroundTNMeasuredTPCalibratedTPTMDLTPBackgroundTPMeasuredChlaCalibratedChlaTMDLChlaBackgroundChla19943,823.52,498.51,783.8152.699.2137.349.439.541.819952,705.91,753.01,662.8107.869.4129.639.929.938.219963,898.72,615.31,824.150168.2112.8134.348.940.74019975802,114.61,352.6754.333.483.753.158.412.2149.88.11998796.62,100.61,350.71,017.522.897.962.978.226.527.119.819.719995853,715.52,492.51,753.729.3169113.3131.813.814.311.811.320007803,811.52,556.81,884.327.1166.1111.4141.719.820.916.916.52001696.34,715.53,163.22,019.723.8184.1123.5148.41716.513.412.520026452,391.41,518.5862.026.595.259.96818.318.612.710.62003642.52,291.51,476.71,546.099.663.9116.61717.112.516.4Minimum5802,100.61,350.7754.322.883.753.158.412.2149.88.1Maximum796.64,715.53,163.22,019.750184.1123.5148.426.549.440.741.8Mean675.13,156.82,077.81,510.830.4132.486.9114.417.826.720.721.5

## Appendix F: SWET Watershed Assessment Model (WAM) Final Report for the Lake Hancock and Saddle Creek Basin (available upon request)

Appendix G: QEA, LLC, BATH TUB Model Final Report for the Lake Hancock and Saddle Creek Basin (available upon request)
Appendix H: WAM Watershed Assessment Model, Model Documentation and Users Manual, Soil and Water Engineering Technology, Inc., May, 2005 (available upon request)